Phenyl-benzimidazolyl-furanes for optical brightening of organic materials

ABSTRACT

2-Phenyl-5-benzimidazol-2&#39;-yl-furanes of the formula ##STR1## in which R 1  to R 6  are as defined in the specification, n is the number 0 or 1 and A⊖ is a colorless anion equivalent to the cation of the fluorescent brightener, their preparation as well as their use for optically brightening organic materials are disclosed.

This is a divisional of application Ser. No. 876,587 filed on Feb. 10,1978 now U.S. Pat. No. 4,189,589, issued Feb. 19, 1980.

The present invention relates to novel phenylbenzimidazolyl-furanes,processes for their preparation and their use for optically brighteningorganic material.

2-Aryl-5-benzimidazol-2'-yl-furanes and their use as fluorescentbrightening agents are known for German Offenlegungsschriften Nos.1,469,227, 1,545,846, 1,594,841 and 2,346,316 and from Coll. Czech.Chem. Commens 38, 1700-1704 (1973).

It has now been found that 2-phenyl-5-benzimidazol-2'-yl-furanes whichare substituted in a specific way surprisingly have better propertiesand produce better effects.

The novel 2-phenyl-5-benzimidazol-2'-yl-furanes are of the formula##STR2## in which R₁ is a sulphonic acid group or an ester or amidethereof, a carboxylic acid group or an ester or amide thereof, a cyanogroup, a trifluoromethyl group or an alkyl- or arylsulphonyl group, R₂is alkyl having 1 to 8 carbon atoms, alkenyl having 3 or 4 carbon atoms,cyclohexyl, hydroxyalkyl having 2 to 4 carbon atoms, alkoxyalkyl havinga total of 3 to 6 carbon atoms, carboxyalkyl having 2 to 6 carbon atoms,carbalkoxyalkyl having a total of 3 to 6 carbon atoms, cyanoalkyl having2 to 4 carbon atoms, carbamoylalkyl which has 1 to 6 carbon atoms in thealkyl moiety and is unsubstituted or substituted on the nitrogen atom by1 or 2 alkyl having 1 to 3 carbon atoms, benzyl which is unsubstitutedor substituted by chlorine, methyl or methoxy, dialkylaminoalkyl havinga total of 3 to 7 carbon atoms or phenethyl and, if n is the number 0,also hydrogen, R₃ is hydrogen, alkyl having 1 to 6 carbon atoms,hydroxyalkyl having 2 or 3 carbon atoms, cyanoalkyl having 2 to 4 carbonatoms, carboxyalkyl having 2 or 3 carbon atoms, carbamoylmethyl which isunsubstituted or substituted on the nitrogen atom by 1 or 2 alkyl having1 to 3 carbon atoms, alkoxycarbonylalkyl having a total of 3 to 6 carbonatoms, alkenyl having 3 or 4 carbon atoms or benzyl which isunsubstituted or substituted by chlorine or methyl, R₄ is hydrogen,chlorine, bromine, fluorine, carboxyl, carbalkoxy having a total of 2 to5 carbon atoms, alkoxyalkoxycarbonyl having a total of 4 to 6 carbonatoms, benzyloxycarbonyl, cyano, sulpho, alkylsulphonyl having 1 to 4carbon atoms, carbamoyl or sulphamoyl which are unsubstituted orsubstituted by 1 or 2 alkyl groups having 1 to 4 carbon atoms, orsulphonic acid phenyl ester or trifluoromethyl, R₅ is hydrogen, chlorineor methyl, R₆ is hydrogen or chlorine, n is the number 0 or 1 andA.sup.⊖ is a colourless anion equivalent to the cation of thefluorescent brightener.

A "sulphonic acid group" is to be understood as meaning the radical--SO₃ M in which M is hydrogen or a salt-forming cation. Possiblesalt-forming cations M are in general those of alkaline earth metals,for example of calcium, barium or magnesium, and especially of alkalimetals, for example of sodium or potassium, but also ammonium, which isunsubstituted or substituted by alkyl or hydroxyalkyl having 1 to 4carbon atoms, or amine salt ions of cyclic amines, such as pyridine,morpholine and piperidine. In addition to hydrogen, M is preferably inparticular the potassium cation or the sodium cation.

In compounds of the formula (1) in which R₁ or R₄ is the group --SO₃ H,the strongly acid sulpho group can form an inner salt with the basicimidazole ring.

"Sulphonic acid esters" and "carboxylic acid esters" R₁ are to beunderstood as meaning those which are formed from aliphatic ormononuclear alicyclic alcohols and from phenols, preferably phenol.Preferred alcohols are branched and non-branched saturated alcoholshaving 1 to 8 carbon atoms, glycol monoalkyl ethers having 3 to 8 carbonatoms, glycol monophenyl ether, phenylalkyl alcohols having 1 to 3carbon atoms in the alkyl moiety, halogenoalkanols, preferablychloroalkanols, having 1 to 4 carbon atoms, cyclohexanol, unsaturatedalcohols having 3 to 6 carbon atoms, glycollic acid, glycollic acidesters having 3 to 8 carbon atoms and glycollic acid nitrile.

Preferred phenols are those of the formula ##STR3## in which X₁ ishydrogen, alkyl having 1 to 8 carbon atoms, halogen, preferablychlorine, alkoxy having 1 to 4 carbon atoms, carboxyl, carbalkoxy having2 to 5 carbon atoms, phenyl or cyanoethyl, X₂ is hydrogen, alkyl having1 to 4 carbon atoms, chlorine or methoxy and X₁ and X₂ together are theradical of a fused benzene or pyridine radical.

Examples of such phenols are phenol, o-, m- and p-cresol, o-, m- andp-chlorophenol, o-, m- and p-methoxy-phenol, 2-ethoxyphenol,2,4-dimethylphenol, 2-sec.-butylphenol, 4-sec.-butylphenol,2-tert.-butylphenol, 4-tert.-butylphenol, 4-ethylphenol,2-isopropylphenol, 5-isopropyl-2-methylphenol, 4-tert.-octylphenol,2,4-dichlorophenol, 4-chloro-o-cresol, 4-chloro-5-methoxyphenol,salicyclic acid, methyl salicylate, 4-hydroxybenzoic acid, ethyl4-hydroxybenzoate, butyl 4-hydroxybenzoate, methyl 3-hydroxybenzoate,4-hydroxybenzonitrile, 2-hydroxybiphenyl, 4-hydroxybiphenyl, vanillinicacid, o-cresotinic acid, m-cresotinic acid,3-(4-hydroxyphenyl)propionitrile, 3-(4-hydroxyphenyl)-propionic acid,naphthol and 8-hydroxyquinoline.

Alkylsulphonyl is to be understood as meaning, preferably, a grouphaving 1 to 4 carbon atoms which can also be substituted by phenyl,chlorophenyl, chlorine or alkoxy having 1 to 4 carbon atoms.Arylsulphonyl groups are preferably phenylsulphonyl groups, which areunsubstituted or can be substituted by halogen, especially chlorine, oralkyl having 1 to 4, preferably 1, carbon atoms.

The colourless anions A.sup.⊖ are those of organic or inorganic acidswhich, corresponding to their valency, are able to form monovalent orpolyvalent salts with the basic benzimidazole. Examples are: aliphaticmonocarboxylic acids having 1 to 18 carbon atoms, which can also besubstituted by 1 to 5 hydroxyl groups or keto groups, for example onicand uronic acids, aromatic carboxylic acids (substituted orunsubstituted benzoic acids), aliphatic di-, tri- and tetracarboxylicacids having 1 to 6 carbon atoms, which preferably can be substituted by1 to 4 hydroxyl groups (for example, saccharic acid), carbonic acid,hydrogen halide acids, sulphuric acid, monoalkyl esters or sulphuricacid having 1 to 4 carbon atoms, arylsulphonic acids (substituted orunsubstituted benzenesulphonic acid), alkylsulphonic acids (for examplemethanesulphonic acid), phosphoric acid, phosphorous acid, nitric acidand the like.

As a rule, the anion is introduced by quaternisation. Accordingly, thepreferred anions are primarily the anions of the quaternising agentsused, such as esters of C₁ -C₄ alcohols with sulphuric acid,benzenesulphonic acid, toluenesulphonic acid, chlorobenzenesulphonicacid, hydrochloric acid and hydrobromic acid.

If desired, however, the anion can also be replaced by another anion byknown methods (c.f., for example, Houben-Weyl, Methoden der organischenChemie (Methods of Organic Chemistry), Volume XI/2, pages 620-626).Preferred anions in this case are those of formic acid, acetic acid,propionic acid, glycollic acid, lactic acid, malic acid, tartaric acid,mucic acid, gluconic acid, citric acid and laevulinic acid.

2-Phenyl-5-benzimidazol-2'-yl-furanes of particular interest are thoseof the formula ##STR4## in which R₁ ' is a sulphonic acid group, asulphonic acid alkyl ester having 1 to 8 carbon atoms, a sulphonic acidcyclohexyl ester, a sulphonic acid alkoxyalkyl ester having a total of 2to 8 carbon atoms, a sulphonic acid phenoxyalkyl ester or phenylalkylester having 1 to 3 carbon atoms in the alkyl moiety, a sulphonic acidchloroalkyl ester having 1 to 4 carbon atoms, a sulphonic acid alkenylester having 3 or 4 carbon atoms, alkylsulphonyl having 1 to 4 carbonatoms, benzylsulphonyl, phenylsulphonyl which is unsubstituted orsubstituted by methyl or chlorine, cyano, trifluoromethyl or --COOY₁,--SO₂ NY₁ Y₂ or --CONY₁ Y₂, in which Y₁ is hydrogen, alkyl having 1 to 8carbon atoms, alkenyl having 3 or 4 carbon atoms, cyclohexyl,hydroxyalkyl having 2 to 4 carbon atoms, alkoxyalkyl having a total of 3to 6 carbon atoms, carboxyalkyl having 2 to 6 carbon atoms,carbalkoxyalkyl having a total of 3 to 6 carbon atoms, cyanoalkyl having2 to 4 carbon atoms, benzyl which is unsubstituted or substituted bychlorine, methyl or methoxy, phenyl which is unsubstituted orsubstituted by chlorine, methyl or methoxy, dialkylaminoalkyl having atotal of 3 to 7 carbon atoms, N-cyano-ethyl-N-alkylaminoalkyl having atotal of 7 to 10 carbon atoms, N-morpholino-, N-piperidino- orN-pyrrolidino-alkyl having 2 or 3 carbon atoms in the alkyl moiety,which can be quaternised or protonated by R₃, or phenethyl and Y₂ ishydrogen, alkyl having 1 to 4 carbon atoms, alkenyl having 3 or 4 carbonatoms or hydroxyalkyl having 2 to 4 carbon atoms, and Y₁ and Y₂ togetherwith the nitrogen atom are a piperidine ring, pyrrolidine ring orN-alkylpiperazine ring having 1 to 3 carbon atoms in the alkyl moiety,or a morpholine ring which is unsubstituted or substituted by 1 or 2methyl groups, or the grouping ##STR5## in which X₁ ' is hydrogen, alkylhaving 1 to 4 carbon atoms, chlorine, alkoxy having 1 to 4 carbon atoms,carboxyl, carbalkoxy having 2 to 5 carbon atoms or phenyl and X₂ ' ishydrogen, methyl, methoxy or chlorine, R₂ ' is alkyl having 1 to 8carbon atoms, alkenyl having 3 or 4 carbon atoms, carbamoylalkyl havinga total of 2 to 6 carbon atoms, hydroxalkyl having 2 to 4 carbon atoms,alkoxyalkyl having a total of 3 to 6 carbon atoms, carboxyalkyl having 2to 6 carbon atoms, carbalkoxyalkyl having a total of 3 to 6 carbonatoms, cyanoalkyl having 2 to 4 carbon atoms, benzyl which isunsubstituted or substituted by chlorine, methyl or methoxy,dialkylaminoalkyl having a total of 3 to 7 carbon atoms or phenethyland, if n is the number 0, also hydrogen, R₃ ' is hydrogen, alkyl having1 to 6 carbon atoms, hydroxyalkyl having 2 or 3 carbon atoms, cyanoalkylhaving 2 to 4 carbon atoms, carboxymethyl, carbamoylmethyl,alkoxycarbonylmethyl having a total of 3 to 6 carbon atoms, alkenylhaving 3 or 4 carbon atoms or benzyl which is unsubstituted orsubstituted by chlorine or methyl, R₄ ' is hydrogen, chlorine, bromine,fluorine, carboxyl, carbalkoxy having a total of 2 to 5 carbon atoms,alkoxyalkoxycarbonyl having a total of 4 to 6 carbon atoms,benzyloxycarbonyl, cyano, sulpho, alkylsulphonyl having 1 to 4 carbonatoms, carbamoyl or sulphamoyl which are unsubstituted or substituted byalkyl having 1 to 4 carbon atoms, or sulphonic acid phenyl ester ortrifluoromethyl, R₅ is hydrogen, chlorine or methyl, n is the number 0or 1 and A.sup.⊖ is a colourless anion equivalent to the cation of thefluorescent brightener.

Preferred 2-phenyl-5-benzimidazol-2'-yl-furanes of the formula (2) arethose of the formula ##STR6## in which R₁ " is alkylsulphonyl having 1to 4 carbon atoms, phenylsulphonyl, benzylsulphonyl, trifluoromethyl,cyano or --CONY₁ 'Y₂ ' or --SO₂ NY₁ 'Y₂ ', in which Y.sub. ' ishydrogen, alkyl having 1 to 4 carbon atoms, alkenyl having 3 or 4 carbonatoms, hydroxyalkyl having 2 to 4 carbon atoms, cyclohexyl, alkoxyalkylhaving a total of 3 to 6 carbon atoms, benzyl or dialkylaminoalkylhaving a total of 3 to 7 carbon atoms, which can be quaternised orprotonated by R₃ ", and Y₂ ' is hydrogen, alkyl having 1 to 3 carbonatoms or alkenyl having 3 or 4 carbon atoms, and Y₁ ' and Y₂ ' togetherwith the nitrogen atom are a piperidine ring, a N-alkylpiperazine ringhaving 1 to 3 carbon atoms in the alkyl moiety or a morpholine ring, ora sulphonic acid alkyl ester having 1 to 4 carbon atoms which isunsubstituted or substituted by alkoxy having 1 to 4 carbon atoms, orthe grouping ##STR7## in which X₁ " is hydrogen, alkyl having 1 to 4carbon atoms, chlorine, methoxy, carboxyl, carbalkoxy having 2 to 5carbon atoms or phenyl and X₂ " is hydrogen, methyl or chlorine, R₂ " isalkyl having 1 to 4 carbon atoms, alkenyl having 3 or 4 carbon atoms,cyanoalkyl having 2 to 4 carbon atoms, carbalkoxyalkyl having a total of3 to 6 carbon atoms, carbamoylmethyl, carboxymethyl or benzyl and, if nis the number 0, also hydrogen, R₃ " is hydrogen, alkyl having 1 to 4carbon atoms, hydroxyalkyl having 2 or 3 carbon atoms, alkenyl having 3or 4 carbon atoms, cyanoalkyl having 2 to 4 carbon atoms,alkoxycarbonylalkyl having a total of 3 to 6 carbon atoms,carbamoylmethyl or benzyl, R₄ " is hydrogen, chlorine, carbalkoxy having2 to 5 carbon atoms or carbamoyl which is unsubstituted or substitutedby alkyl having 1 to 4 carbon atoms, R₅ is hydrogen, chlorine or methyl,n is the number 0 or 1 and A.sup.⊖ is a colourless anion equivalent tothe cation of the fluorescent brightener, and also the compounds of theformula ##STR8## in which R₁ '" is a sulphonic acid alkoxyalkyl esterhaving a total of 2 to 6 carbon atoms, a sulphonic acid alkyl esterhaving 1 to 4 carbon atoms, alkylsulphonyl having 1 to 4 carbon atoms,phenylsulphonyl, cyano or --CONY₁ "Y₂ " or --SO₂ NY₁ "Y₂ ", in which Y₁" is hydrogen, alkyl having 1 to 4 carbon atoms, alkenyl having 3 or 4carbon atoms, hydroxyalkyl having 2 to 4 carbon atoms, alkoxyalkylhaving a total of 3 to 6 carbon atoms, benzyl or dialkylaminoalkylhaving a total of 3 to 7 carbon atoms, which can be quaternised orprotonated by R₃ '", and Y₂ " is hydrogen or alkyl having 1 to 3 carbonatoms, and Y₁ ' and Y₂ " together with the nitrogen atom are amorpholine ring, or the grouping ##STR9## in which X₁ '" is hydrogen,alkyl having 1 to 4 carbon atoms, chlorine or methoxy and X₂ '" ishydrogen, methyl or chlorine, R₂ '" and R₃ '" independently of oneanother are alkyl having 1 to 4 carbon atoms, cyanoalkyl having 2 to 4carbon atoms, alkoxycarbonylmethyl having 1 to 3 carbon atoms in thealkyl moiety, carbamoylmethyl or benzyl, n is the number 0 or 1 andA.sup.⊖ is a colourless anion equivalent to the cation of thefluorescent brightener.

In compounds of the formulae (1), (3) and (4), Y₂, Y₂ ' and Y₂ "respectively are preferably hydrogen.

In compounds of the formula (3), R₅ is preferably hydrogen or methyl.

Particularly preferred compounds of the formula (2) are those of theformula ##STR10## in which R₁ '.sup.ν is a sulphonic acid alkyl esterhaving 1 to 8 carbon atoms, a sulphonic acid cyclohexyl ester, asulphonic acid alkoxyalkyl ester having a total of 2 to 8 carbon atoms,a sulphonic acid phenoxyalkyl ester or sulphonic acid phenylalkyl esterhaving 1 to 3 carbon atoms in the alkoxy or alkyl moiety, a sulphonicacid chloroalkyl ester having 1 to 4 carbon atoms, a sulphonic acidalkenyl ester having 3 or 4 carbon atoms, trifluoromethyl or thegrouping ##STR11## and R₂ ', R₃ ', R₄ ', R₅, X₁ ', X₂ ', n and A.sup.⊖are as defined under formula (2).

Compounds of particular interest are those of the formula ##STR12## inwhich R₁.sup.ν is a sulphonic acid alkyl ester having 1 to 4 carbonatoms which is unsubstituted or substituted by alkoxy having 1 to 4carbon atoms, or trifluoromethyl or the grouping ##STR13## and R₂ ", R₃", R₅, X₁ ", X₂ .increment., n and A.sup.⊖ are as defined under formula(3), and especially compounds of the formula ##STR14## in which R₁.sup.ν' is a sulphonic acid alkyl ester having 1 to 4 carbon atoms which isunsubstituted or substituted by alkoxy having 1 or 2 carbon atoms, ortrifluoromethyl or the grouping ##STR15## and R₂ '", R₃ '", X₂ '", n andA.sup.⊖ are as defined under formula (4).

2-Phenyl-5-benzimidazol-2'-yl-furanes of the formula (2) which are ofparticular interest are those of the formula ##STR16## in which Q ishydrogen, alkyl having 1 to 4 carbon atoms, phenyl, cyclohexyl, alkenylhaving 3 or 4 carbon atoms, alkoxyalkyl having a total of 3 to 6 carbonatoms, benzyl or dialkylaminoalkyl having a total of 3 to 7 carbonatoms, which can be quaternised or protonated by R₃ ", and R₂ ", R₃ ",R₄ ', R₅, n and A.sup.⊖ are as defined further above, and also thecompounds of the formula ##STR17## in which Q' is hydrogen or alkylhaving 1 to 4 carbon atoms and R₂ '", R₃ '", n and A.sup.⊖ are asdefined under formula (4).

Preferred compounds are those of the formulae (1) to (9) in which n isthe number 1 and especially the compounds of the formulae ##STR18## inwhich Q' is hydrogen or alkyl having 1 to 4 carbon atoms and R₂ '.sup.νis methyl or benzyl, ##STR19## in which R₁.sup.ν " is methylsulphonylphenylsulphonyl or cyano, ##STR20##

The compounds of the formula (1) are obtainable by various processes,thus, for example, by subjecting a compound of the formula ##STR21## inwhich R₄, R₅ and R₆ are as defined under formula (1), to a condensationreaction with an o-phenylenediamine of the formula ##STR22## in which R₁and R₂ are as defined under formula (1), to give azomethines of theformula ##STR23## and then oxidising or dehydrogenating the latter tothe corresponding 2-phenyl-5-benzimidazol-2'-yl-furanes of the formula(1) in which n is the number 0 and, if desired, quaternising the latterwith an alkylating agent to give compounds of the formula (1) in which nis the number 1.

The condensation reaction of compounds of the formula (14) with those ofthe formula (15) to give compounds of the formula (16) is advantageouslycarried out at a temperature between 0° and 60° C., preferably at 10° to30° C. In general it is advisable to carry out the condensation reactionin a solvent and diluent, such as methanol, ethanol, acetone,acetonitrile, glacial acetic acid, ethyl acetate, dioxane,tetrahydrofurane, dimethylformamide, benzene, toluene, xylene,chlorobenzene, o-dichlorobenzene, chloroform or carbon tetrachloride.

The conversion of the azomethines of the formula (16) to thecorresponding benzimidazole compounds of the formula (1) is effected bymethods known per se, using oxidants, for example oxygen and preferablyatmospheric oxygen, in the presence of oxygen-transfer catalysts such ascobalt naphthenates or conventional heavy metal complex catalysts, suchas are described in German Offenlegungsschrift No. 2,138,931, manganesedioxide, copper-II acetate, lead tetraacetate, sodium hypochlorite,chloranil or nitrobenzene, and can be carried out in a solvent which isinert towards the particular oxidant such as methanol, ethanol, acetone,glacial acetic acid, dioxane, tetrahydrofurane, dimethylformamide,benzene, toluene, xylene, chlorobenzene, o-dichlorobenzene, chloroform,carbon tetrachloride and pyridine. The reaction is carried out at atemperature between 15° C. and the boiling point of the solvent used,preferably between 20° and 30° C.

According to a modification of this process, compounds of the formula(1) can also be obtained by reacting compounds of the formula (14) withthose of the formula (15) in the presence either of copper-II salts asoxidants (c.f. Elderfield, Heterocyclic Compounds, Volume 5, 283) orpreferably of dithionites or especially bisulphites or the anhydridesthereof, such as alkali metal dithionites, alkali metal bisulphites oralkali metal metabisulphites.

In this case the reaction is advantageously carried out using aconcentrated aqueous solution of at least 1 mol of sodium bisulphite orat least 1/2 mol of sodium dithionite, and preferably 1 to 3 mols ofsodium bisulphite per mol of starting material (14) and (15), and also,if desired, an inert organic solvent, at temperatures between 60° C. and120° C. and preferably at the reflux temperature. Suitable inert organicsolvents are those listed above, especially those which are partially orwholly miscible with water, for example ethanol, n-propanol, n-butanol,dioxane, ethyl acetate, dimethylformamide, ethylene glycol monomethylether or cyclohexanone.

Compounds of the formula (1) in which n is the number 0 can also beobtained by reacting those compounds in which R₂ is hydrogen withalkylating agents in the presence of basic compounds, by known methods.

The formation of the acid addition products or quaternary ammoniumsalts, especially the reaction of compounds of the formula (1) in whichn is the number 0 with a protonating or quaternising agent of theformula

    R.sub.3 --A

in which R₃ is as defined above and A is the radical which is convertedinto the anion A.sup.⊖ during the quaternisation, can be carried out ina conventional manner, preferably in a solvent, and advantageously atleast one mol equivalent of the protonating or quaternising agent isemployed.

If it is desired to prepare compounds of the formula (1) in which R₂ isnot hydrogen and which are quaternised with alkyl radicals, thealkylation is preferably carried out with dialkyl sulphates, such asdimethyl sulphate and diethyl sulphate, alkyl halides, such as methylchloride, ethyl iodide or bromide, propyl iodide or bromide and butyliodide or bromide, allyl chloride or bromide or crotyl chloride orbromide, or alkylbenzenesulphonates, such as a p-methyl-, ethyl- orchloro-benzenesulphonate. If it is desired to prepare compounds of theformula (1) in which R₂ is not hydrogen and which are quaternised by abenzyl radical, the benzylation is preferably carried out with benzylhalides, such as benzyl chloride. Examples of further quaternisingagents are BrCH₂ CH₂ OH, BrCH₂ CHOHCH₃ and especially halogenoaceticacid derivatives, such as ClCH₂ CO₂ CH₂ CH₃, BrCH₂ COOH, BrCH₂ COOCH₃,ClCH₂ CN, ClCH₂ CONH₂, ClCH₂ CONHCH₃ and ClCH₂ CON(CH₃)₂, and alsoethylene oxide or propylene oxide in the presence of suitable anions,such as, for example, those of formic acid, acetic acid or lactic acid.

If it is desired to prepare protonated compounds of the formula (1),i.e. acid addition salts thereof, the protonation is carried out inparticular with mineral acids. Suitable acids are, in principle, allstrong to medium-strength organic acids or mineral acids, it beingpossible to exchange the anions by double decomposition.

Suitable solvents in which the protonation or quaternisation can becarried out are in general all inert solvents. Preferred solvents arethose which dissolve the starting material and from which the endproduct separates out immediately. Examples are: aromatic hydrocarbons,such as benzene, toluene and xylene; halogenated hydrocarbons, such astrichloroethane, tetrachloroethylene, chlorobenzene or dichlorobenzene,and also nitro compounds, such as nitromethane, nitropropane andnitrobenzene, alkanols and open-chain or cyclic ethers, such as butanol,dibutyl ether, ethylene glycol, ethylene glycol monomethyl ether,ethylene glycol monoethyl ether, anisole or dioxane; ketones, such ascyclohexanone or methyl ethyl ketone; fatty acid amides, such asdimethylformamide or dimethylacetamide; sulphoxides, such asdimethylsulphoxide, and carboxylic acid esters, such as ethyl acetate orbutyl acetate. The reaction is carried out, for example, at temperaturesof 60° to 180° C. and preferably of 90° to 140° C. In some cases it isalso advantageous to use excess alkylating agent as the solvent.

Compounds of the formula (1) in which n is the number 0 and which have asufficiently basic nitrogen atom in the radical R₁ can be quaternised onthis nitrogen atom in the side chain, without the benzimidazole ringalso being quaternised. Such compounds have the formula ##STR24## inwhich R₁ ^(X1) is SO₂ NZ₁ Z₂, CONZ₁ Z₂ or COOZ₁, in which Z₁ isN,N'-dialkylaminoalkyl having a total of 3 to 7 carbon atoms or aN-morpholinoalkyl, N-piperidinoalkyl or N-pyrrolidinoalkyl radical, eachhaving 2 to 3 carbon atoms in the alkyl moiety, and Z₂ is hydrogen,alkyl having 1 to 4 carbon atoms, hydroxyalkyl having 2 to 4 carbonatoms or cyanoalkyl having 2 to 3 carbon atoms, and Z₁ and Z₂ togetherwith the nitrogen atom are a N-alkylpiperazine orN-hydroxyalkylpiperazine ring having 1 to 4 carbon atoms in the alkylmoiety, and R₂, R₄, R₅ and R₆ are as defined above. Compounds in whichZ₂ is hydrogen are preferred.

The quaternisation is generally carried out with the same alkylatingagents R₃ --A which are used for the quaternisation of the benzimidazolering. However, advantageously somewhat milder reaction conditions aremaintained, i.e. lower temperatures of about 50° to 100° C. and thestoichiometric amount or only a slight excess of the alkylating agent.

If, however, it is desired to obtain di-quaternised compounds, at least2 mols of the alkylating agent R₃ --A are used per mol of the compoundof the formula (17) and in other respects the reaction is carried outunder reaction conditions the same as those under which thebenzimidazole ring is quaternised.

Compounds of the formula (1) can also be prepared by subjecting afurane-5-carboxylic acid of the formula ##STR25## or a functionalderivative thereof, in which R₄, R₅ and R₆ are as defined under formula(1), to a condensation reaction with an o-phenylenediamine of theformula ##STR26## in which R₁ and R₂ are as defined under formula (1),advantageously in the presence of catalysts, for example acetic acid,hydrogen chloride, boric acid, zinc chloride, polyphosphoric acid orp-toluenesulphonic acid, and quaternising the compounds of the formula(1) in which n is the number 0, which are thus obtained, by reactionwith an alkylating agent in the manner indicated above. Functionalderivatives of the carboxylic acid are to be understood as meaning thesalts, halides, esters, amides, imino-ethers and nitriles thereof.

The compounds of the formula (1) can also be prepared by acylating acorrespondingly substituted o-nitroaniline with correspondinglysubstituted 2-phenyl-furane-5-carboxylic acid or a functional derivativethereof, reducing the nitro group, preferably in an acid medium, forexample with stannous chloride, and at the same time effectingcyclisation to give the imidazole ring.

The starting materials of the formula (15) are generally prepared in amanner known per se, by reacting 4-chloro-3-nitrobenzene derivativeswith primary amines or ammonia to give the correspondingly substitutedo-nitroanilines and reducing the latter, for example by means ofcatalytic hydrogenation (c.f. Belgian Patent Specification No. 595,327,German Offenlegungsschrift No. 2,239,614 and German OffenlegungsschriftNo. 1,522,412). The reduction of o-nitroanilines having substituentswhich are readily hydrogenated catalytically, for example allyl groups,is better carried out with sodium hydrosulphide or iron (Bechampmethod).

The compounds of the formula (15) are, for example, those in which R₁and R₂ are as defined below:

R₁ : Carbamoyl, sulphamoyl or methyl-, ethyl-, n-propyl-, isopropyl-,n-butyl-, isobutyl-, sec.-butyl-, octyl-, hydroxyethyl-,γ-hydroxypropyl-, methoxyethyl-, isopropoxypropyl-, β-hydroxypropyl-,3-butoxy-1-propyl-, 3-methoxypropyl-, 3-ethoxypropyl-,α,α-dimethyl-β-hydroxyethyl-, α,α-(dihydroxymethyl)-ethyl-,carboxymethyl-, β-carboxyethyl-, ω-carboxypentyl-,ethoxycarbonylmethyl-, β-cyanoethyl-, phenyl-, o- and p-methoxyphenyl-,o-chlorophenyl-, benzyl-, phenethyl-, p-methylbenzyl-, cyclohexyl-,allyl-, dimethylaminopropyl-, diethylaminoethyl-,2-(N-morpholinoethyl)-, 2-(N-pyrrolidinoethyl)-, 2-(N-piperidinoethyl)-or diethylaminopropyl-carbamoyl or -sulphamoyl; dimethyl-, diethyl-,dihydroxyethyl-, N-methyl-N-phenyl-, N-ethyl-N-phenyl-,N-methyl-N-(β-hydroxyethyl)-, N-ethyl-N-(β-hydroxyethyl)-,N-n-propyl-N-hydroxymethyl- or diallyl-carbamoyl or -sulphamoyl;morpholino-, 3,5-dimethylmorpholino-, pyrrolidino-, piperidino-,2-ethylpiperidino-, N-methylpiperazino- orN-(β-hydroxyalkyl)piperazino-carbonyl or -sulphonyl; sulpho, sodiumsulphonate, phenyl sulphonate, o-methylphenyl sulphonate, m-methylphenylsulphonate, p-tolylsulphonate, o- and p-chlorophenyl sulphonate,o-methoxyphenyl sulphonate, 2,4-dimethylphenyl sulphonate,p-tert.-butylphenyl sulphonate, 2-isopropyl-5-methylphenyl sulphonate,methylsulphonyl, ethylsulphonyl, propylsulphonyl, butylsulphonyl,benzylsulphonyl, tosyl, p-chlorophenylsulphonyl, cyano ortrifluoromethyl.

R₂ : Hydrogen, methyl, ethyl, isopropyl, n-propyl, n-butyl, sec.-butyl,isobutyl, octyl, hydroxyethyl, γ-hydroxypropyl, β-hydroxypropyl,methoxyethyl, isopropoxypropyl, α,α-dimethyl-β-hydroxyethyl,α,α-(dihydroxymethyl)-ethyl, carboxymethyl, β-carboxyethyl,ω-carboxypentyl, ethoxycarbonylmethyl, cyanoethyl, benzyl, phenethyl,p-methylbenzyl, cyclohexyl, allyl, dimethylaminopropyl,diethylaminoethyl, diethylaminopropyl or carbamoylmethyl.

The compounds of the formula (14) are obtained by reacting diazotisedanilines with furfurol in the presence of copper-I chloride (CA 48(1954) 1935 and U.S. Pat. No. 3,856,825). The compounds of the formula(18) are obtained analogously from diazotised anilines andfurane-2-carboxylic acid (Collect, Czech.Chem.Commun.39 (1974) 767-72,1892-97) or by oxidising 2-phenylfurane-5-aldehydes.

Examples of compounds of the formulae (14) and (18) are those of theformulae ##STR27## which can be substituted as indicated below:2-chloro, 3-chloro, 4-chloro, 2,4-dichloro, 2,5-dichloro, 2,3-dichloro,3-chloro-4,6-disulphonamido, 3-chloro-4,6-disulpho, 2-bromo, 4-bromo,2-carboxy, 3-carboxy, 4-carboxy, 4-(carboxylic acid methyl ester),4-(carboxylic acid ethyl ester), 4-(carboxylic acid benzyl ester),4-(carboxylic acid methoxyethyl ester), 4-(carboxylic acid butyl ester),2-cyano, 3-cyano, 4-cyano, 2-(carboxylic acid methyl ester),2-carboxamido, 3-carboxamido, 4-carboxamido, 2-sulpho, 3-sulpho,4-sulpho, 3-sulphonamido, 4-ethylsulphonamido, 4-chloro-2-cyano,4-sulphonamido, 4-dimethylsulphonamido, 2-(sulphonic acid phenyl ester),4-(sulphonic acid phenyl ester), 2-methylsulphonyl, 4-methylsulphonyl,2-phenylsulphonyl, 4-phenylsulphonyl, 2,4-di-(methylsulphonyl),2-carboxy-5-sulphonamido, 2-sulpho-4-methyl, 2-carboxy-4-methyl,2-carboxy-5-methyl, 3-carboxy-5-sulpho, 2-methyl-4-sulpho,4-chloro-3-carboxy, 2-chloro-4-methylsulphonyl, 2 -methyl-3-chloro,2-methyl-5-chloro, 3-chloro-4-methyl-4-chloro, 2-methyl-3-carbomethoxy,3-sulpho-4-chloro, 2-chloro-5-sulpho, 2-sulpho-4-chloro,3,4-dichloro-6-sulpho, 2,5-dichloro-4-sulpho, 4-chloro-3-carboxy,5-chloro-2-carboxy, 2-chloro-5-carboxy, 2-fluoro, 3-fluoro,3,5-dicarboxy, 3,5-dicarbomethoxy, 2-methyl-4,5-dichloro,2,4,5-trichloro, 2,4-difluoro, 2,4-(disulphonic acid diphenyl ester) or2-chloro-4-(sulphonic acid phenyl ester).

The novel compounds defined above exhibit a more or less pronouncedfluorescence in solution or when finely dispersed. They can be used foroptically brightening a wide variety of synthetic, regenerated man-madeor natural organic materials, or substances which contain such organicmaterials.

Without any restriction being implied by the following classification,examples of organic materials which can be optically brightened are:

I. Synthetic organic materials of high molecular weight:

(a) Polymerisation products based on organic compounds containing atleast one polymerisable carbon-carbon double bond, i.e. theirhomopolymers or copolymers as well as their after-treatment products,for example crosslinking, grafting or degradation products, polymerblends, or products obtained by modification of reactive groups, forexample polymers based on α,β-unsaturated carboxylic acids orderivatives of such carboxylic acids, especially on acrylic compounds(for example acrylates, acrylic acid, acrylonitrile, acrylamides andtheir derivatives or their methacrylic analogues), on olefinhydrocarbons (for example ethylene, propylene, styrenes or dienes andalso ABS polymers), and polymers based on vinyl and vinylidene compounds(for example vinyl chloride, vinyl alcohol and vinylidene chloride);

(b) Polymerisation products which can be obtained by ring opening, forexample polyamides of the polycaprolactam type, and also polymers whichare obtained either by polyaddition or by polycondensation, such aspolyethers or polyacetals;

(c) Polycondensation products or precondensates based on bifunctional orpolyfunctional compounds with condensable groups, the homocondensationand co-condensation products and aftertreatment products thereof, forexample polyesters, in particular saturated polyesters (for examplepolyesters of ethylene glycol and terephthalic acid) or unsaturatedpolyesters (for example maleic acid/dialcohol polycondensates and theircrosslinking products with copolymerisable vinyl monomers), unbranchedand branched polyesters (also including those based on polyhydricalcohols, for example alkyd resins), polyamides (for examplehexamethylenediamine adipate), maleic resins, melamine resins, theprecondensates and analogues thereof, polycarbonates and silicones;

(d) Polyaddition products, such as polyurethanes (crosslinked andnon-crosslinked) and epoxide resins.

II. Regenerated man-made organic materials, for example cellulose estersof varying degrees of esterification (so-called 21/2-acetate ortriacetate) or cellulose ethers, regenerated cellulose (viscose orcuprammonium cellulose), or their aftertreatment products, and caseinplastics.

III. Natural organic materials of animal or vegetable origin, forexample based on cellulose or proteins, such as cotton, wool, linen,silk, varnish gums, starch and casein.

The organic materials to be optically brightened can be in the mostdiverse states of processing (raw materials, semi-finished goods orfinished goods). On the other hand, they can be in the form ofstructures of the most diverse shapes, for example predominantlythree-dimensionally expanded structures, such as sheets, profiles,injection mouldings, various machined articles, chips, granules orfoams, and also predominantly two-dimensional structures, such as films,foils, lacquers, coatings and impregnations, or predominantlyone-dimensional bodies, such as filaments, fibres, flocks and wires. Thesaid materials can, on the other hand, also be in an unshaped state, inthe most diverse homogeneous or inhomogeneous forms of division, as forexample in the form of powders, solutions, emulsions, dispersions,latices, pastes or waxes.

Fibrous materials can be, for example, in the form of endless filaments(stretched or unstretched), staple fibres, flocks, hanks, textilefilaments, yarns, threads, non-wovens, felts, waddings, flockedstructures or woven textile or bonded textile fabrics, knitted fabricsand papers, cardboards or paper pulps.

The compounds to be used according to the invention are of importance,inter alia, for the treatment of organic textile materials, especiallywoven textile fabrics. If fibres which can be in the form of staplefibres or endless filaments or in the form of hanks, woven fabrics,knitted fabrics, non-wovens, flocked substrates or bonded fabrics, areto be optically brightened according to the invention, this isadvantageously effected in an aqueous medium, in which the compounds inquestion are present in a finely divided form (suspensions, so-calledmicrodispersions, or optionally solutions). If desired, dispersingagents, stabilisers, wetting agents and further assistants can be addedduring the treatment.

Depending on the type of brightener compound used, it can beadvantageous to carry out the treatment in a neutral or alkaline or acidbath. The treatment is usually carried out at temperature between about20° and 140° C., for example at the boiling point of the bath or near it(about 90° C.). Solutions or emulsions in organic solvents can also beused for the finishing, according to the invention, of textilesubstrates, as is practised in the dyeing industry in so-called solventdyeing (pad-thermofixation, or exhaust dyeing processes in dyeingmachines).

The novel fluorescent brightening agents of the present invention canfurther be added to, or incorporated in, the materials before or duringtheir shaping, thus they can for example be added to the compressionmoulding composition or injection moulding composition during themanufacture of films, sheets (for example incorporated in polyvinylchloride in a roll mill at elevated temperature) or mouldings.

If the fashioning of man-made synthetic or regenerated man-made organicmaterials is effected by spinning processes or from spinningsolutions/melts, the fluorescent brightening agents can be applied bythe following processes:

Addition to the starting substances (for example monomers) orintermediates (for example precondensates or prepolymers), i.e. beforeor during the polymerisation, polycondensation or polyaddition,

Sprinkling in powder form on polymer chips or granules for spinningsolutions/melts,

Bath dyeing of polymer chips or granules for spinning solutions/melts,

Metered addition to spinning melts or spinning solutions, and

Application to the spun tow before stretching.

The novel fluorescent brightening agents of the present invention can,for example, also be employed in the following use forms:

(a) In mixtures with dyes (shading) or pigments (coloured pigments orespecially, for example, white pigments), or as an additive to dyebaths,printing pastes, discharge pastes or reserve pastes, or for theaftertreatment of dyeings, prints or discharge prints;

(b) In mixtures with carriers, wetting agents, plasticisers, swellingagents, antioxidants, light stabilisers, heat stabilisers and chemicalbleaching agents (chlorite bleach or bleaching bath additives);

(c) In admixture with crosslinking agents or finishing agents (forexample starch or synthetic finishes), and in combination with a widevariety of textile finishing processes, especially resin finishes (forexample creaseproof finishes such as wash-and-wear, permanent-press ornon-iron), as well as flameproof finishes, soft-handle finishes,anti-soiling finishes or antistatic finishes, or antimicrobial finishes;

(d) Incorporation of the flourescent brightening agents into polymericcarriers (polymerisation, polycondensation or polyaddition products), indissolved or dispersed form, for use, for example, in coating agents,impregnating agents or binders (solutions, dispersions and emulsions)for textiles, non-wovens, papers and leather;

(e) As additives to master batches;

(f) As additives to a wide variety of industrial products in order torender these more marketable (for example improving the appearance ofsoaps, detergents and pigments);

(g) In combination with other fluorescent brightening substances;

(b) In spinning bath preparations, i.e. as additives to spinning bathswhich are used for improving the slip for the further processing ofsynthetic fibres, or from a special bath before the stretching of thefibre;

(i) As scintillators for various purposes of a photographic nature, forexample for electrophotographic reproduction or supersensitising; and

(j) Depending on the substitution, as laser dyes.

If the brightening process is combined with textile treatment orfinishing methods, the combined treatment can in many casesadvantageously be carried out with the aid of appropriate stablepreparations which contain the fluorescent brightener compounds in sucha concentration that the desired white effect is achieved.

In certain cases, the fluorescent brighteners are made fully effectiveby an aftertreatment. This can be, for example, a chemical treatment(for example acid treatment), a thermal treatment, or a combinedchemical/thermal treatment. Thus, for example, the appropriate procedureto follow in brightening a number of fibre substrates, for examplepolyester fibres, with the fluorescent brightening agents of the presentinvention, is to impregnate these fibres with the aqueous dispersions(or optionally also solutions) of the brighteners at temperatures below75° C., for example at room temperature, and to subject them to a dryheat treatment at temperatures above 100° C., it being generallyadvisable additionally to dry the fibrous material beforehand at amoderately elevated temperature, for example at not less than 60° C. toabout 130° C. The heat treatment in the dry state is then advantageouslycarried out at temperatures between 120° and 225° C., for example byheating in a drying chamber, by ironing within the specified temperaturerange or by treatment with dry, superheated steam. The drying and dryheat treatment can also be carried out in immediate succession orcombined in a single operation.

The amount of novel fluorescent brightening agent to be used accordingto the invention, based on the weight of the material to be opticallybrightened, can vary within wide limits. A marked and lasting effect canbe obtained even with very insignificant amounts, in certain cases0.0001 percent by weight. It is also possible to use amounts of up toapproximately 0.8 percent by weight and, on occasion, up toapproximately 2 percent by weight. For most practical purposes, it ispreferable to use amounts between 0.0005 and 0.5 percent by weight.

For various reasons it is often advantageous not to use the fluorescentbrighteners by themselves, i.e. pure, but in admixture with a widevariety of assistants and extenders, for example anhydrous sodiumsulphate, sodium sulphate decahydrate, sodium chloride, sodiumcarbonate, alkali metal phosphates, such as sodium or potassiumorthophosphate, sodium or potassium pyrophosphate and sodium orpotassium tripolyphosphates or alkali metal silicates.

Compounds of the formula (1) in which n is the number 1 are preferredand these effect pronounced brightening not only on polyacrylonitrilebut especially on modified polyacrylonitrile ("Courtelle®") andpolyamide.

The quaternised compounds of the formula (1) are generally resistant tochlorite.

In a further aspect the present invention relates to novel2-phenyl-5-benzimidazol-2'-yl-furanes of the formula ##STR28## in whichR₁ is a sulphonic acid group, a sulphonic acid phenyl ester and isunsubstituted or non-chromophoric substituted, alkylsulphonyl having 1to 4 carbon atoms, benzylsulphonyl, phenylsulphonyl which isunsubstituted or substituted by methyl or chlorine, cyano,trifluoromethyl, --SO₂ NY₁ Y₂ or --CONY₁ Y₂, in which Y₁ is hydrogen,alkyl having 1 to 8 carbon atoms, alkenyl having 3 to 4 carbon atoms,cyclohexyl, hydroxyalkyl having 2 to 4 carbon atoms, alkoxyalkyl havinga total of 3 to 6 carbon atoms, carboxyalkyl having 2 to 6 carbon atoms,carbalkoxyalkyl having a total of 3 to 6 carbon atoms, cyanoalkyl having2 or 3 carbon atoms, benzyl, which is unsubstituted or substituted bymethyl or methoxy, phenyl which is unsubstituted or substituted bychlorine, methyl or methoxy, dialkylaminoalkyl having a total of 3 to 7carbon atoms or phenethyl, Y₂ is hydrogen, alkyl having 1 to 3 carbonatoms, alkenyl having 3 or 4 carbon atoms or hydroxyalkyl having 2 to 4carbon atoms and Y₁ and Y₂ together with the nitrogen atom are a 5- or6-membered aliphatic heterocyclic ring, which optionally can contain afurther heteroatom and which is unsubstituted or substituted bynon-chromophoric substituents, R₂ is alkyl having 1 to 8 carbon atoms,alkenyl having 3 or 4 carbon atoms, cyclohexyl, hydroxyalkyl having 2 to4 carbon atoms, alkoxyalkyl having a total of 3 to 6 carbon atoms,carbalkoxy having 2 to 6 carbon atoms, carbalkoxyalkyl having a total of3 to 6 carbon atoms, cyanoalkyl having 2 or 3 carbon atoms, benzyl whichis unsubstituted or substituted by chlorine, methyl or methoxy,dialkylaminoalkyl having a total of 3 to 7 carbon atoms or phenethyland, if n is the number 0, also hydrogen, R₃ is hydrogen, alkyl having 1to 6 carbon atoms, hydroxyalkyl having 2 or 3 carbon atoms, cyanoalkylhaving 2 or 3 carbon atoms, carboxyalkyl having 2 or 3 carbon atoms,carbamoylalkyl having 2 to 4 carbon atoms, alkoxycarbonylalkyl having atotal of 3 to 6 carbon atoms, alkenyl having 3 or 4 carbon atoms orbenzyl which is unsubstituted or substituted by chlorine or methyl, R₄is chlorine, bromine, fluorine, carboxyl, carbalkoxy having a total of 2to 5 carbon atoms, alkoxyalkoxycarbonyl having a total of 4 to 6 carbonatoms, benzyloxycarbonyl, cyano, sulpho, alkylsulphonyl having 1 to 4carbon atoms, phenylsulphonyl which is unsubstituted or substituted bychlorine or methyl, benzylsulphonyl, sulphonic acid phenyl ester whichis unsubstituted or non-chromophoric substituted, or --SO₂ NY₁ Y₂ or--CONY₁ Y₂ wherein Y₁ and Y₂ have the meaning given above, R₅ ishydrogen, chlorine, alkylsulphonyl having 1 to 4 carbon atoms, sulpho,methyl, sulphonic acid phenyl ester which is unsubstituted ornon-chromophoric substituted or --SO₂ NY₁ Y₂ wherein Y₁ and Y₂ have themeaning given above, R₆ is hydrogen or chlorine, n is the number 0 or 1and A.sup.⊖ is a colourless anion, to compounds of the formula ##STR29##wherein R₁ ' is sulpho, sulphonic acid phenyl ester, alkylsulphonylhaving 1 to 4 carbon atoms, phenylsulphonyl, benzylsulphonyl,trifluoromethyl, cyano or --SO₂ NY₁ 'Y₂ ' wherein Y₁ ' is hydrogen,alkyl having 1 to 4 carbon atoms, alkenyl having 3 or 4 carbon atoms,cyclohexyl, alkoxyalkyl having a total of 3 to 6 carbon atoms or benzyland Y₂ ' is hydrogen, alkyl having 1 to 3 carbon atoms or alkenyl having3 or 4 carbon atoms and Y₁ ' and Y₂ ' together with the nitrogen atomare a piperidine ring, pyrrolidine ring or a morpholine ring which isunsubstituted or substituted by 2 methyl groups, R₂ ' is alkyl having 1to 4 carbon atoms, alkenyl having 3 or 4 carbon atoms, cyclohexyl,alkoxyalkyl having a total of 3 to 6 carbon atoms or benzyl and, if n isthe number 0, also hydrogen, R₃ ' is hydrogen, alkyl having 1 to 4carbon atoms, hydroxyalkyl having 2 or 3 carbon atoms, alkenyl having 3or 4 carbon atoms or benzyl, R₄ ' is chlorine, carbalkoxy having 2 to 5carbon atoms, cyano, sulpho, alkylsulphonyl having 1 to 4 carbon atoms,phenylsulphonyl, benzylsulphonyl, sulphonic acid phenyl ester or --SO₂NY₁ 'Y₂ ' or --CONY₁ 'Y₂ ' wherein Y₁ ' and Y₂ ' have the meaning givenabove, R₅ ' is hydrogen or chlorine, n is the number 0 or 1 A'.sup.⊖ ishalide, formiate acetate, lactate, CH₃ SO₄.sup.⊖, C₂ H₅ SO₄.sup.⊖, C₆ H₅SO₃.sup.⊖, p-CH₃ --C₆ H₄ SO₃.sup.⊖, p-Cl--C₆ H₄ SO₃.sup.⊖, carbonate orbicarbonate, to compounds of the formula ##STR30## wherein R₁ " issulphonic acid phenyl ester, alkylsulphonyl having 1 to 4 carbon atoms,phenyl sulfonyl, benzyl sulphonyl, cyano or --SO₂ NY₁ 'Y₂ ' wherein Y₁ 'is hydrogen, alkyl having 1 to 4 carbon atoms, alkenyl having 3 or 4carbon atoms, cyclohexyl, alkoxyalkyl having a total of 3 to 6 carbonatoms or benzyl, Y₂ ' is hydrogen, alkyl having 1 to 3 carbon atoms oralkenyl having 3 or 4 carbon atoms and Y₁ ' and Y₂ ' together with thenitrogen atom are a piperidine ring, a pyrrolidine ring or a morpholinering which is unsubstituted or substituted by two methyl groups, R₂ 'has the meaning given above, R₃ ' is hydrogen, alkyl having 1 to 4carbon atoms, hydroxyalkyl having 2 or 3 carbon atoms, alkenyl having 3or 4 carbon atoms or benzyl, R₄ " is chlorine, carbalkoxy having 2 to 5carbon atoms, cyano, alkylsulphonyl having 1 to 4 carbon atoms,phenylsulphonyl, benzylsulphonyl, sulphonic acid phenyl ester or --SO₂NY₁ 'Y₂ ' or --CONY₁ 'Y₂ ' wherein Y₁ ' and Y₂ ' have the meaning givenabove, R₅ ' is hydrogen or chlorine, n is the number 0 or 1 and A".sup.⊖is chloride, bromide, jodide, formiate, acetate, lactate, CH₃ SO₄.sup.⊖,C₂ H₅ SO₄.sup.⊖, C₆ H₅ SO₃.sup.⊖, p-CH₃ --C₆ H₄ SO₃.sup.⊖, p-Cl--C₆ H₄SO₃.sup.⊖, carbonate or bicarbonate, to compounds of the formula##STR31## wherein R₁ '" is sulphonic acid phenyl ester, alkylsulphonylhaving 1 to 4 carbon atoms, cyano, trifluoromethyl or --SO₂ NY₁ "Y₂ ",wherein Y₁ " is hydrogen, alkyl having 1 to 4 carbon atoms, alkenylhaving 3 or 4 carbon atoms, hydroxyalkyl having 2 to 4 carbon atoms,phenyl or cyclohexyl, Y₂ " is hydrogen, alkyl having 1 to 4 carbon atomsor hydroxyalkyl having 2 to 4 carbon atoms, and Y₁ " and Y₂ " togetherwith the nitrogen atom are the morpholine ring, R₂ " is alkyl having 1to 4 carbon atoms, hydroxyalkyl having 1 to 4 carbon atoms, alkenylhaving 3 or 4 carbon atoms, benzyl or cyclohexyl, R₃ " is alkyl having 1to 4 carbon atoms, hydroxyalkyl having 1 to 4 carbon atoms,alkoxycarbonylalkyl having 3 to 6 carbon atoms or benzyl, R₄ '" ischlorine, carboxyl, carbalkoxy having 2 to 5 carbon atoms, sulpho,alkylsulphonyl having 1 to 4 carbon atoms, phenylsulphonyl,benzylsulphonyl, cyano, sulphonic acid phenyl ester, carbamoyl or --SO₂NHY₁ '" wherein Y₁ '" is hydrogen or alkyl having 1 to 4 carbon atoms,R₅ '" is hydrogen, chlorine or methyl, n is the number 0 or 1 andA'".sup.⊖ is chloride, bromide, iodide, CH₃ SO₄.sup.⊖, C₂ H₅ SO₄.sup.⊖or p-CH₃ --C₆ H₄ --SO₃.sup.⊖, to compounds of the formula ##STR32##wherein R₁ ' is trifluoromethyl or sulphonic acid phenyl ester which isunsubstituted or substituted by one to three alkyl groups having 1 to 4carbon atoms, chlorine or methoxy, R₂ is alkyl having 1 to 8 carbonatoms, alkenyl having 3 or 4 carbon atoms, cyclohexyl, hydroxyalkylhaving 2 to 4 carbon atoms, alkoxyalkyl having a total of 3 to 6 carbonatoms, carbalkoxy having 2 to 6 carbon atoms, carbalkoxyalkyl having atotal of 3 to 4 carbon atoms, cyanoalkyl having 2 or 3 carbon atoms,benzyl which is unsubstituted or substituted by chlorine, methyl ormethoxy, dialkylamino alkyl having a total of 3 to 7 carbon atoms orphenethyl and, if n is the number 0, also hydrogen, R₃ is hydrogen,alkyl having 1 to 6 carbon atoms, hydroxyalkyl having 2 or 3 carbonatoms, cyanoalkyl having 2 or 3 carbon atoms, carboxyalkyl having 2 or 3carbon atoms, carbamoylalkyl having 2 to 4 carbon atoms,alkoxycarbonylalkyl having a total of 3 to 6 carbon atoms, alkenylhaving 3 or 4 carbon atoms or benzyl which is unsubstituted orsubstituted by chlorine or methyl, R₄ is chlorine, bromine, fluorine,carboxyl, carbalkoxy having a total of 2 to 5 carbon atoms,alkoxyalkoxycarbonyl having a total of 4 to 6 carbon atoms,benzyloxycarbonyl, cyano, sulpho, alkylsulphonyl having 1 to 4 carbonatoms, phenylsulphonyl which is unsubstituted or substituted by chlorineor methyl, benzylsulphonyl, sulphonic acid phenyl ester which isunsubstituted or non-chromophoric substituted or --SO₂ NY₁ Y₂ or --CONY₁Y₂ wherein Y₁ and Y₂ have the meaning given above, R₅ is hydrogen,chlorine, alkylsulphonyl having 1 to 4 carbon atoms, sulpho, methyl,sulphonic acid phenyl ester which is unsubstituted or non-chromophoricsubstituted or --SO₂ NY₁ Y₂ wherein Y₁ and Y₂ have the meaning givenabove, R₆ is hydrogen or chlorine, n is the number 0 or 1 and A.sup.⊖ isa colourless anion.

The present invention relates also to process for the preparation ofcompounds of formula (A) as defined above, which comprise

(a) condensing a compound of the formula ##STR33## wherein R₄, R₅ and R₆have the meaning given under formula (A), with an o-phenylenediamine ofthe formula ##STR34## wherein R₁ and R₂ are as defined under formula(A), to give azomethines of the formula ##STR35## and then oxidising ordehydrogenating the latter to the corresponding2-phenyl-5-benzimidazol-5-benzimidazol-2'-yl-furanes of the formula (A)in which n is the number 0 and, if desired, quaternising the latter withan alkylating agent to give compounds of the formula (A) in which n isthe number 1, or

(b) condensing a furane-5-carboxylic acid of the formula ##STR36## or afunctional derivative thereof, in which R₄, R₅ and R₆ are as definedunder formula (A) with an o-phenylenediamine of the formula ##STR37## inwhich R₁ and R₂ are as defined under formula (A) and quaternising theresulting compound of the formula (A) in which n is the number 0, ifdesired with an alkylating agent, to a compound of the formula (A) inwhich n is the number 1.

In the Examples, percentages are always by weight. The melting pointsare uncorrected and in the case of the quaternary compounds are usuallynot sharp.

EXAMPLE 1

21.3 ml of an aqueous 40% strength solution of sodium bisulphite areadded to a hot solution of 26.7 g of 2(4'-chlorophenyl)-furane-5-aldehyde (purity 77.4%) and 29.25 g of phenyl3-amino-4-ethylaminobenzenesulphonate in 200 ml of ethylene glycolmonomethyl ether. The mixture is stirred at the reflux temperature for 2hours, diluted with 40 ml of water and allowed to cool. The productwhich has precipitated out is filtered off with suction, washedrepeatedly with methanol and water and dried in vacuo at 100° C. Thisgives 40.4 g (84% of theory) of the compound of the formula ##STR38##which after recrystallisation from perchloroethylene and ethylene glycolmonomethyl ether is isolated in the form of virtually colourlesscrystals having a melting point of 171° C.

EXAMPLE 2

20.7 g of 2-(4'-chlorophenyl)-furane-5-aldehyde and 20.1 g of2-methylamino-4-methylsulphonyl-aniline in 60 ml of ethanol are refluxedfor 20 minutes. 40 ml of nitrobenzene are added, the ethanol isdistilled off and the temperature is raised to the boiling point of thenitrobenzene. After 5 minutes at the reflux temperature, the mixture isallowed to cool, 40 ml of methanol are added and the precipitate whichhas formed is filtered off with suction, washed with methanol and driedin vacuo. This gives 22.3 g of the compound of the formula ##STR39##which after recrystallisation from o-dichlorobenzene and ethylene glycolmonomethyl ether is isolated in the form of virtually colourlesscrystals having a melting point of 234° C.

Compounds of the formula ##STR40## in which the substituents R₁, R₂, R₄,R₅, R₆ and R₇ are as defined in Table I, are obtained according toExample 1 or 2 from the corresponding 2-phenyl-furane-5-aldehydes ando-phenylenediamines of the formulae (14a) and (15) respectively:

                                      TABLE I                                     __________________________________________________________________________    Compound                                   Melting                            of the formula                             point                              No.     R.sub.4                                                                              R.sub.5                                                                          R.sub.6                                                                          R.sub.7                                                                         R.sub.2 R.sub.1     °C.                         __________________________________________________________________________    (203)   Cl     H  Cl H CH.sub.3                                                                              SO.sub.2 CH.sub.3                                                                         233                                (204)   Cl     H  H  H CH.sub.3                                                                              SO.sub.2 OC.sub.6 H.sub.5                                                                 191                                (205)   COOC.sub.2 H.sub.5                                                                   H  H  H CH.sub.3                                                                              SO.sub.2 CH.sub.3                                                                         241                                (206)   CN     H  H  H CH.sub.3                                                                              SO.sub.2 CH.sub.3                                                                         307                                (207)   Cl     Cl H  H CH.sub.3                                                                              SO.sub.2 CH.sub.3                                                                         243                                (208)   Cl     H  H  H CH.sub.3                                                                              SO.sub.2 NHCH.sub.3                                                                       241                                (209)   Cl     H  H  H CH.sub.2 C.sub.6 H.sub.5                                                              SO.sub.2 N(CH.sub.3).sub.2                                                                216                                (210)   Cl     H  H  H CH.sub.3                                                                              CONHCH.sub.3                                                                              239                                (211)   Cl     H  H  H CH.sub.3                                                                              CN          212                                (212)   SO.sub.2 NH.sub.2                                                                    H  H  H CH.sub.3                                                                              SO.sub.2 CH.sub.3                                                                         342                                (213)   Cl     H  H  H CH.sub.3                                                                              SO.sub.2 N(C.sub.6 H.sub.5)(C.sub.2                                           H.sub.5)    189                                (214)   SO.sub.3 H                                                                           H  H  H CH.sub.3                                                                              SO.sub.2 CH.sub.3                                                                         >360                               (215)   Cl     H  H  H CH.sub.3                                                                              CF.sub.3    184                                (216)   Cl     H  Cl H CH.sub.3                                                                              SO.sub.2 OC.sub.6 H.sub.5                                                                 221                                (217)   SO.sub.2 OC.sub.6 H.sub.5                                                            H  H  H CH.sub.3                                                                              SO.sub.2 CH.sub.3                                                                         192                                (218)   SO.sub.2 CH.sub.3                                                                    H  H  H CH.sub.3                                                                              SO.sub.2 CH.sub.3                                                                         301                                (219)   Cl     H  CH.sub.3                                                                         H CH.sub.3                                                                              SO.sub.2 CH.sub.3                                                                         208                                (220)   H      H  Cl H CH.sub.3                                                                              SO.sub.2 CH.sub.3                                                                         205                                (221)   SO.sub.2 NHCH.sub.3                                                                  H  H  H CH.sub.3                                                                              SO.sub.2 CH.sub.3                                                                         299                                (222)   Cl     H  H  H CH.sub.3                                                                              COOCH.sub.3 271                                (223)   Cl     H  H  H CH.sub.3                                                                              COOH        329                                (224)   Cl     H  Cl Cl                                                                              CH.sub.3                                                                              SO.sub.2 CH.sub.3                                                                         255                                (225)   Cl     H  H  H CH.sub.2 C.sub.6 H.sub.5                                                              CF.sub.3    204                                (226)   COOH   H  H  H CH.sub.3                                                                              SO.sub.2 OC.sub.6 H.sub.5                                                                 294                                (227)   Cl     CF.sub.3                                                                         H  H CH.sub.3                                                                              SO.sub.2 CH.sub.3                                                                         283                                (228)   Cl     H  H  H H       SO.sub.2 CH.sub.3                                                                         223                                (229)   Cl     H  H  H CH.sub.3                                                                              SO.sub.2 C.sub.6 H.sub.5                                                                  232                                (230)   H      H  H  H CH.sub.3                                                                              SO.sub.2 OC.sub.6 H.sub.5                                                                 189                                (231)   Cl     H  H  H CH.sub.2 C.sub.6 H.sub.5                                                              SO.sub.2 CH.sub.3                                                                         207                                (232)   Cl     H  H  H CH.sub.2 C.sub.6 H.sub.5                                                              SO.sub.2 OC.sub.6 H.sub.5                                                                 177                                (233)   Cl     H  H  H CH.sub.3                                                                               ##STR41##  199                                (234)   Cl     H  H  H CH.sub.3                                                                              SO.sub.2 N(CH.sub.3).sub.2                                                                232                                (235)   Cl     H  H  H C.sub.2 H.sub.5                                                                       COOH        330                                (236)   Cl     H  H  H CH.sub.2 C.sub.6 H.sub.5                                                              SO.sub.2 NH.sub.2                                                                         272                                (237)   Cl     H  H  H CH.sub.3                                                                              SO.sub.2 NHCH.sub.2 CH.sub.2 OCH.sub.3                                                    231                                (238)   Cl     H  H  H CH.sub.2 C.sub.6 H.sub.5                                                              CONH.sub.2  283                                (239)   CONH.sub.2                                                                           H  H  H CH.sub.3                                                                              SO.sub.2 OC.sub.6 H.sub.5                                                                 226                                (240)   Cl     H  H  H CH.sub.3                                                                              SO.sub.2 C.sub.2 H.sub.5                                                                  213                                (241)   Cl     H  H  H C.sub.2 H.sub.5                                                                       SO.sub.2 CH.sub.3                                                                         200                                (242)   H      Cl H  H CH.sub.3                                                                              SO.sub.2 OC.sub.6 H.sub.5                                                                 177                                (243)   Cl     H  H  H CH.sub.3                                                                              SO.sub.2 NH(CH.sub.2).sub.3 N(CH.sub.3).sub                                   .2          232                                (244)   Cl     H  H  H CH.sub.3                                                                              SO.sub.2 NHCH.sub.2 CH.sub.2 OH                                                           207                                (245)   Cl     H  H  H CH.sub.2 C.sub.6 H.sub.5                                                              COOCH.sub.3 227                                (246)   Cl     H  H  H CH.sub.2 C.sub.6 H.sub.5                                                              CN          217                                (247)   Cl     H  H  H n-C.sub.4 H.sub.9                                                                     SO.sub.3 H* >360                               (248)   H      H  H  H CH.sub.3                                                                              SO.sub.2 CH.sub.3                                                                         237                                (249)   Cl     H  H  H CH.sub.2 C.sub.6 H.sub.5                                                              COOH        312                                (250)   Cl     H  H  H CH.sub.2 CHCH.sub.2                                                                   SO.sub.2 NHCH.sub.2 CHCH.sub.2                                                            208                                (251)   Cl     H  H  H CH.sub.2 C.sub.6 H.sub.5                                                              SO.sub.2 NHCH.sub.2 C.sub.6 H.sub.5                                                       210                                (252)   Cl     H  H  H CH.sub.2 COOCH.sub.3                                                                  SO.sub.2 OC.sub.6 H.sub.5                                                                 255                                (253)   CH.sub.3                                                                             H  H  H CH.sub.3                                                                              SO.sub.2 OC.sub.6 H.sub.5                                                                 200                                (254)   Cl     H  CH.sub.3                                                                         H CH.sub.3                                                                              SO.sub.2 OC.sub.6 H.sub.5                                                                 203                                (255)   Cl     H  H  H CH.sub.2 CN                                                                           SO.sub.2 OC.sub. 6 H.sub.5                                                                171                                (256)   Cl     H  H  H CH.sub.2 COOH                                                                         SO.sub.2 OC.sub.6 H.sub.5                                                                 271                                                                           (decomposition)                    __________________________________________________________________________     *The sulphonic acid of the formula (247) is obtained according to Example     1 initially in the form of the soluble sodium salt. In order to               precipitate it, the reaction mixture is acidified with hydrochloric acid.

The o-nitroanilines and the o-phenylenediamines obtained therefrom byreduction, which are required for the preparation of the compoundsmentioned in Examples 1, 2 and 3 and have the formulae ##STR42## arelisted in Table II:

                                      TABLE II                                    __________________________________________________________________________                             Melting point °C.                                                      for compound                                         No.                                                                              R.sub.1        R.sub.2                                                                              A       B                                            __________________________________________________________________________    1  SO.sub.2 CH.sub.3                                                                            CH.sub.3                                                                             193      98                                          2  SO.sub.2 NHCH.sub.3                                                                          CH.sub.3                                                                             181     103                                          3  SO.sub.3 Na    CH.sub.3                                                                             324     290                                                                           (decomposition)                              4  CN             CH.sub.3                                                                             168     140                                          5  SO.sub.2 N(C.sub.6 H.sub.5)(C.sub.2 H.sub.5)                                                 CH.sub.3                                                                             142     105                                          6  CONHCH.sub.3   CH.sub.3                                                                             206     155                                          7  SO.sub.2 N(CH.sub.3).sub.2                                                                   CH.sub.2 C.sub.6 H.sub.5                                                             157     195                                          8  CF.sub.3       CH.sub.3                                                                             74       50                                          9  COOH           CH.sub.3                                                                             310     197                                                                           (decomposition)                              10 COOCH.sub.3    CH.sub.3                                                                             145     102                                          11 SO.sub.2N(CH.sub.3).sub.2                                                                    CH.sub.3                                                                             152     159                                          12 COOH           C.sub.2 H.sub.5                                                                      234     194                                                                           (decomposition)                              13 SO.sub.2 OC.sub.6 H.sub.5                                                                    CH.sub.3                                                                             101      110*                                        14 SO.sub.2NH(CH.sub.2).sub.3N(CH.sub.3).sub.2                                                  CH.sub.3                                                                             115      99                                          15 SO.sub.3 Na    n-C.sub.4 H.sub.9                                                                    300     296                                                                   (decomposition)                                                                       (decomposition)                              16 SO.sub. 2 NH.sub.2                                                                           CH.sub.2 C.sub.6 H.sub.5                                                             190     154                                          17 SO.sub.2 NH CH.sub.2 CHCH.sub.2                                                              CH.sub.2 CHCH.sub.2                                                                  86       75                                          18 SO.sub.2 NH.sub.2                                                                            n-C.sub.4 H.sub.9                                                                    178     116                                          19 COOH           CH.sub.2C.sub.6 H.sub.5                                                              208     204                                          20 SO.sub.2NHCH.sub.2 CH.sub.2OCH.sub.3                                                         CH.sub.3                                                                             103     liquid                                                                        (crude)                                      21 CONH.sub.2     CH.sub.2C.sub.6 H.sub.5                                                              200     186                                          22 SO.sub.2 NHCH.sub.2 C.sub.6 H.sub.5                                                          CH.sub.2C.sub.6 H.sub.5                                                              135     141                                          23 SO.sub.2 OC.sub.6 H.sub.5                                                                    CH.sub.2C.sub.6 H.sub.5                                                              125     139                                          24 CF.sub.3       CH.sub.2C.sub.6 H.sub.5                                                              80       94                                          25 SO.sub.2 OC.sub.6 H.sub.4 -o-CH.sub.3                                                        CH.sub.3                                                                             101     110                                          26 SO.sub.2 OC.sub.6 H.sub.5                                                                    C.sub.2 H.sub.5                                                                      104     114                                          27 SO.sub.2 CH.sub.3                                                                            CH.sub.2C.sub.6 H.sub.5                                                              135     171                                          28 SO.sub.2 C.sub.2 H.sub.5                                                                     CH.sub.3                                                                             125     102                                          29 SO.sub.2 CH.sub.3                                                                            C.sub.2 H.sub.5                                                                      162     131                                          30 SO.sub.2 NHCH.sub.2 CH.sub.2 OH                                                              CH.sub.3                                                                             145     120                                          31 COOCH.sub. 3   CH.sub.2C.sub.6 H.sub.5                                                              101     129                                          32 CN             CH.sub.2C.sub.6 H.sub.5                                                              128     not isolated                                 33 SO.sub.2 OC.sub.6 H.sub.5                                                                    CH.sub.2 COOCH.sub.3                                                                 122     not isolated                                 34 SO.sub.2 OC.sub.6 H.sub.5                                                                    CH.sub.2 CN                                                                          133     not isolated                                 35 SO.sub.2 OC.sub.6 H.sub.5                                                                    CH.sub.2 COOH                                                                        175     not isolated                                 __________________________________________________________________________     *Melting point of the hydrochloride: 185° C. (decomposition)      

The 2-phenylfurane-5-aldehyde derivatives which are obtained by reactingfurfurol with corresponding diazotised anilines in aqueous solution inthe presence of copper-I chloride and which were not known hitherto aredescribed in Table III.

                  TABLE III                                                       ______________________________________                                         ##STR43##                                                                    Compound                              Melting point                           No.      R.sub.2                                                                              R.sub.3                                                                              R.sub.4   R.sub.5                                                                            °C.                              ______________________________________                                        1        H      H      SO.sub.2 OC.sub.6 H.sub.5                                                               H    112                                     2        CH.sub.3                                                                             H      Cl        H    114                                     3        H      H      SO.sub.2 NHCH.sub.3                                                                     H    153                                     4        Cl     H      Cl        Cl   133                                     5        H      CF.sub.3                                                                             Cl        H     90                                     6        H      H      CONH.sub.2                                                                              H    180                                     ______________________________________                                    

EXAMPLE 3

22.3 g of 2-(4'-chlorophenyl)-furance-5-carboxylic acid in 9.7 ml ofthionyl chloride, 60 ml of toluene and 0.8 ml of dimethylformamide arerefluxed for 1 hour and the solution is completely evaporated in vacuo.The solid residue (the acid chloride) is introduced in portions into asolution of 24.3 g of 3-amino-4-n-butylaminobenzene-sulphonamide in 150ml of glacial acetic acid, 9.0 g of anhydrous sodium acetate are alsoadded and the resulting mixture is stirred for 1 hour at roomtemperature. The mixture is now heated at the reflux temperature for 3hours and allowed to cool and 150 ml of water are added. The productwhich has separated out is filtered off with suction, washed repeatedlywith water and dried. This gives 39.7 g (92% of theory) of the compoundof the formula ##STR44## Melting point 260° C., after recrystallisationfrom o-dichlorobenzene and ethylene glycol monomethyl ether.

EXAMPLE 4

49.9 g of the Na salt of 4-chloro-3-nitrobenzene-sulphonic acid (purity55.3%, based on the free sulphonic acid) are stirred in 90 ml of a 20%strength aqueous solution of methylamine and 15 ml of dioxane for 1 hourat 60° C. The mixture is heated at the reflux temperature for a further2 hours, the solution is allowed to cool to about 5° C. and thevoluminous crystalline product is filtered off with suction. Afterwashing the residue twice with acetone and drying in vacuo at 100° C.,21.8 g of the compound of the formula ##STR45## are obtained. Theproduct can be recrystallised from n-propanol/water, 8:2.

A solution of 405.4 g of the crude product of the formula (401) in 2,500ml of water is hydrogenated at 50° C. in the presence of 40.5 g of Raneynickel under normal pressure. The catalyst is filtered off and theaqueous solution is evaporated to dryness in vacuo in a rotaryevaporator. This gives 351.6 g of a dark coloured crude product of theformula ##STR46## The compound is obtained in the form of the freesulphonic acid by recrystallising a sample from 20% strengthhydrochloric acid.

22.5 g of the crude compound of the formula (402) are reacted with 20.7g of 2-(4'-chlorophenyl)-furane-5-aldehyde, according to Example 2. Theresulting product (23.4 g) of the formula ##STR47## is recrystallisedfrom n-propanol/water, 8:2, and dissolved in water. 6 ml of concentratedhydrochloric acid are added dropwise, with stirring, and the compound ofthe formula ##STR48## is obtained in the form of its inner salt of theformula ##STR49## This inner salt is washed with glacial acetic acid,water and alcohol and dried in vacuo at 100° C.

EXAMPLE 5

38.8 g of the crude sulphonic acid of the formula (247) in 300 ml ofchlorobenzene, 23 ml of thionyl chloride and 1 ml of dimethylformamideare stirred under reflux for 3 hours, after which time the evolution ofhydrogen chloride has ceased. The resulting solution is allowed to coolto 5° C. and the crystalline precipitate is filtered off with suction,washed with xylene and dried in vacuo at 80° C. This gives 30.6 g of thesulphonyl chloride of the formula ##STR50## After recrystallisation fromxylene, a sample melts at 164° C.

9.0 g of the compound of the formula (501) are warmed in 60 ml ofethylene glycol monomethyl ether and 4.9 ml of pyridine to 80° C. for 15minutes, during which time the compound goes into solution. On coolingto 5° C. and adding 60 ml of water, the reaction product crystallisesout. This is filtered off with suction, washed repeatedly with water anddried over calcium chloride, in vacuo at room temperature. This gives7.5 g (77% of theory) of the sulphonic acid ester of the formula##STR51## After recrystallisation from carbon tetrachloride, the productmelts at 146° C.

The two sulphonic acid esters of the formulae ##STR52## melting point131° C., and ##STR53## melting point 131° C. (crude), are obtained in asimilar manner.

EXAMPLE 6

2.3 ml of dimethyl sulphate are added dropwise to a solution of 7.73 gof the compound of the formula (201) in 40 ml of dimethylformamide, at120° C., with stirring. After the dropwise addition is complete, themixture is stirred at this temperature for a further 1/2 hour, allowedto cool and diluted with 40 ml of isopropanol. The product which hascrystallised out is filtered off with suction, washed with isopropanoland dried in vacuo at 100° C. This gives 9.75 g (95% of theory) of thecompound of the formula ##STR54## The compound can be used direct forbrightening polyacrylonitrile or can be purified by recrystallisationfrom water, from which it precipitates in the form of luminous paleyellow crystals having a melting point of 276° C.

The compounds of the general formula ##STR55## in which R₁, R₂, R₃, R₄,R₅, R₆, R₇ and A are as defined in Table IV, are obtained in a similarmanner.

                                      TABLE IV                                    __________________________________________________________________________    Com-                                                      Melting             pound                                                     point               No. R.sub.1      R.sub.2 R.sub.3  R.sub.4                                                                              R.sub.5                                                                          R.sub.6                                                                          R.sub.7                                                                         A        °C.          __________________________________________________________________________    603 SO.sub.3     CH.sub.3                                                                              CH.sub.3 Cl     H  H  H --       350                 604 SO.sub.3 CH.sub.3                                                                          CH.sub.3                                                                              CH.sub.3 Cl     H  Cl H CH.sub.3 OSO.sub.3                                                                     225                 605 SO.sub.2 OC.sub.6 H.sub.5                                                                  CH.sub.3                                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     214                 606 SO.sub.2 CH.sub.3                                                                          CH.sub.3                                                                              CH.sub.3 COOC.sub.2 H.sub.5                                                                   H  H  H CH.sub.3 OSO.sub.3                                                                     245                 607 SO.sub.2 CH.sub.3                                                                          CH.sub.3                                                                              CH.sub.3 CN     H  H  H CH.sub.3 OSO.sub.3                                                                     241                 608 SO.sub.2 CH.sub.3                                                                          CH.sub.3                                                                              CH.sub.3 Cl     Cl H  H CH.sub.3 OSO.sub.3                                                                     240                 609 SO.sub.2 NHCH.sub.3                                                                        CH.sub.3                                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     246                 610 SO.sub.2 N(CH.sub.3).sub.2                                                                 CH.sub.2 C.sub. 6 H.sub.5                                                             CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     158                 611 CN           CH.sub.3                                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     275                 612 CONHCH.sub.3 CH.sub.3                                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     247                 613 SO.sub.2 CH.sub.3                                                                          CH.sub.3                                                                              C.sub.2 H.sub.4 OH                                                                     Cl     H  H  H Cl       265                                                                           decom-                                                                        position            614 CF.sub.3     CH.sub.3                                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     212                 615 SO.sub.2 CH.sub.3                                                                          CH.sub.3                                                                              CH.sub.3 SO.sub.2 NH.sub.2                                                                    H  H  H CH.sub.3 OSO.sub.3                                                                     198                 616 SO.sub.2 OC.sub.6 H.sub.5                                                                  CH.sub.3                                                                              CH.sub.3 Cl     H  Cl H CH.sub.3 OSO.sub.3                                                                     228                 617 SO.sub.2 NH.sub.2                                                                          n-C.sub.4 H.sub.9                                                                     CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     174                 618                                                                                ##STR56##   CH.sub.3                                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     166                 619 SO.sub.2 CH.sub.3                                                                          CH.sub.3                                                                              CH.sub.3 SO.sub.2 CH.sub. 3                                                                   H  H  H CH.sub.3 OSO.sub.3                                                                     258                 620 SO.sub.2 CH.sub.3                                                                          CH.sub.3                                                                              CH.sub.3 Cl     H  CH.sub.3                                                                         H CH.sub.3 OSO.sub.3                                                                     220                 621 SO.sub.2 CH.sub.3                                                                          CH.sub.3                                                                              CH.sub.3 SO.sub.2 OC.sub.6 H.sub.5                                                            H  H  H CH.sub.3 OSO.sub.3                                                                     240                 622 SO.sub.2 CH.sub.3                                                                          CH.sub.3                                                                              CH.sub.3 H      H  Cl H CH.sub.3 OSO.sub.3                                                                     197                 623 SO.sub.2 CH.sub.3                                                                          CH.sub.3                                                                              CH.sub.3 SO.sub.2 NHCH.sub.3                                                                  H  H  H CH.sub.3 OSO.sub.2                                                                     235                 624 COOCH.sub.3  CH.sub.3                                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     257                 625 COOH         CH.sub.3                                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     266                 626 CF.sub.3     CH.sub.2 C.sub.6 H.sub.5                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     138                 627 SO.sub.2 CH.sub.3                                                                          CH.sub.3                                                                              CH.sub.3 Cl     H  Cl Cl                                                                              CH.sub.3 OSO.sub.3                                                                     252                 628 SO.sub.2 OC.sub.6 H.sub.5                                                                  CH.sub.3                                                                              CH.sub.3 COOH   H  H  H CH.sub.3 OSO.sub.3                                                                     235                 629 SO.sub.2 CH.sub.3                                                                          CH.sub.3                                                                              CH.sub.3 Cl     CF.sub.3                                                                         H  H CH.sub.3 OSO.sub.3                                                                     235                 630 SO.sub. 2 C.sub.6 H.sub.5                                                                  CH.sub.3                                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     278                 631 SO.sub.2 OC.sub.6 H.sub.5                                                                  CH.sub.3                                                                              CH.sub.3 H      H  H  H CH.sub.3 OSO.sub.3                                                                     190                 632 SO.sub.2 OC.sub.6 H.sub.5                                                                  CH.sub.2 C.sub.6 H.sub.5                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     209                 633 SO.sub.2 CH.sub.3                                                                          CH.sub.2 C.sub.6 H.sub.5                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     225                 634 SO.sub.2 OC.sub.6 H.sub.5                                                                  C.sub.2 H.sub.5                                                                       CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                      96                 635                                                                                ##STR57##   CH.sub.3                                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     204                 636 SO.sub.2 N(CH.sub.3).sub.2                                                                 CH.sub.3                                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     219                 637 COOH         C.sub.2 H.sub.5                                                                       CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     203                 638 SO.sub.2 NH.sub.2                                                                          CH.sub.2 C.sub.6 H.sub.5                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     157                 639 SO.sub.2 NH(CH.sub.2).sub.2 OCH.sub.3                                                      CH.sub.3                                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     225                 640 CONH.sub.2   CH.sub.2 C.sub.6 H.sub.5                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     241                 641 SO.sub.2 CH.sub.3                                                                          CH.sub.3                                                                              CH.sub.2 CN                                                                            Cl     H  H  H Cl       248                 642 SO.sub.2 C.sub.2 H.sub.5                                                                   CH.sub.3                                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     255                 643 SO.sub.2 CH.sub.3                                                                          C.sub.2 H.sub.5                                                                       CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     196                 644 SO.sub.2 NH(CH.sub.2).sub.3 N.sup.⊕ (CH.sub.3).sub.3                                   CH.sub.3                                                                              CH.sub.3 Cl     H  H  H 2 CH.sub.3 OSO.sub.3                                                                   250                 645 SO.sub.2 OC.sub.6 H.sub.5                                                                  CH.sub.3                                                                              CH.sub.3 H      Cl H  H CH.sub.3 OSO.sub.3                                                                     182                 646 COOCH.sub.3  CH.sub.2 C.sub.6 H.sub.5                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     202                 647 SO.sub.2 NHCH.sub.2 CH.sub.2 OH                                                            CH.sub.3                                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     174                 648 SO.sub.2 OC.sub.6 H.sub.5                                                                  CH.sub.3                                                                              CH.sub.3 CONH.sub.2                                                                           H  H  H CH.sub.3 OSO.sub.3                                                                     221                 649 SO.sub.2 OC.sub.6 H.sub.5                                                                  CH.sub.3                                                                              CH.sub.2 CONH.sub.2                                                                    Cl     H  H  H Cl       249                                                                           decom-                                                                        position            650 SO.sub.2 OC.sub.6 H.sub.5                                                                  CH.sub.3                                                                              CH.sub.2 C.sub.6 H.sub.5                                                               Cl     H  H  H Br       218                 651 SO.sub.2 OC.sub.6 H.sub.5                                                                  CH.sub.3                                                                              CH.sub.2COOC.sub.2 H.sub.5                                                             Cl     H  H  H Br       199                                                                           decom-                                                                        position            652 SO.sub.2 OC.sub.6 H.sub.5                                                                  CH.sub.3                                                                              C.sub.2 H.sub.5                                                                        Cl     H  H  H                                                                                ##STR58##                                                                             213                 653 CN           CH.sub.2 C.sub.6 H.sub.5                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     213                 654 SO.sub.2 CH.sub.3                                                                          CH.sub.3                                                                              CH.sub.3 H      H  H  H CH.sub.3 OSO.sub.3                                                                     271                 655 COOH         CH.sub.2 C.sub.6 H.sub.5                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     233                 656 SO.sub.2 NHCH.sub.3                                                                        CH.sub.3                                                                              CH.sub.2 CN                                                                            Cl     H  H  H Cl       230                                                                           decom-                                                                        position            657 SO.sub.2 NHCH.sub.2 C.sub.6 H.sub.5                                                        CH.sub.2 C.sub.6 H.sub.5                                                              CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     193                 658 SO.sub.2 NHCH.sub.2 CHCH.sub.2                                                             CH.sub.2 CHCH.sub.2                                                                   CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     185                 659 SO.sub.2 OC.sub.6 H.sub.5                                                                  CH.sub.3                                                                              CH.sub.3 Cl     H  CH.sub.3                                                                         H CH.sub.3 OSO.sub.3                                                                     203                 660 SO.sub.2 CH.sub.3                                                                          CH.sub.3                                                                              CH.sub.2 COOC.sub.2 H.sub.5                                                            Cl     H  H  H Br       225                 661 SO.sub.2 NH.sub.2                                                                          n-C.sub.4 H.sub.9                                                                     CH.sub.2 CN                                                                            Cl     H  H  H Cl       153                                                                           decom-                                                                        position            662 SO.sub.2 NHCH.sub.3                                                                        CH.sub.3                                                                              CH.sub.2 COOC.sub.2 H.sub.5                                                            Cl     H  H  H Br       222                                                                           decom-                                                                        position            663 CN           CH.sub.3                                                                              CH.sub.2 COOC.sub. 2 H.sub.5                                                           Cl     H  H  H Br       207                 664 COOCH.sub.3  CH.sub.3                                                                              CH.sub.2 COOC.sub.2 H.sub.5                                                            Cl     H  H  H Br       209                                                                           decom-                                                                        position            665 SO.sub.2 NHCH.sub.2 CH.sub.2 OCH.sub.3                                                     CH.sub.3                                                                              CH.sub.2 COOC.sub.2 H.sub.5                                                            Cl     H  H  H Br       212                                                                           decom-                                                                        position            666 SO.sub.2 NHCH.sub.2 CH.sub.2 OCH.sub.3                                                     CH.sub.3                                                                              CH.sub.2 CN                                                                            Cl     H  H  H Cl       180                                                                           decom-                                                                        position            667 SO.sub.2 OC.sub.6 H.sub.5                                                                  CH.sub.2 CN                                                                           CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     243                 668 SO.sub.2 OC.sub.6 H.sub.5                                                                  CH.sub.2 COOCH.sub.3                                                                  CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     169                                                                           decom-                                                                        position            669 SO.sub.2 OC.sub.6 H.sub.5                                                                  CH.sub. 3                                                                             CH.sub.3 CH.sub.3                                                                             H  H  H CH.sub.3 OSO.sub.3                                                                     220                 670 SO.sub.2 CH.sub.3                                                                          CH.sub.3                                                                              CH.sub.2 CONH.sub.2                                                                    Cl     H  H  H Cl       310                                                                           decom-                                                                        position            671 SO.sub.2 OC.sub.6 H.sub.5                                                                  CH.sub.2 COOH                                                                         CH.sub.3 Cl     H  H  H CH.sub.3 OSO.sub.3                                                                     194                 __________________________________________________________________________

If the quaternisation with dimethyl sulphate is not carried out indimethylformamide at 120° C., the solvents and temperatures indicated inTable V below are used, a reaction time of about 2 hours beingmaintained (unless specifically indicated otherwise).

                  TABLE V                                                         ______________________________________                                        Solvent     Temperature Compound No.                                          ______________________________________                                        Dioxane     reflux      605, 614, 618, 622, 626,                                                      632, 633, 634, 635                                    Anisole/DMF 120° C.                                                                            608, 612, 617, 619, 624,                                                      627, 629, 639, 648                                    Anisole     120° C.                                                                            609, 616, 621, 630, 636,                                                      671                                                   Chlorobenzene                                                                             120° C.                                                                            610, 611, 642, 643, 646,                                                      653, 654, 657, 658, 667                               Dioxane/DMF reflux      620                                                   Xylene      120° C.                                                                            631, 645, 659, 668, 669                               DMF         100  C.     647                                                   ______________________________________                                    

Twice the amount of dimethyl sulphate was employed in order to preparethe compound of the formula (644).

When mixtures with dimethylformamide were used, dimethylformamide was ineach case added to the other solvent until the starting material justwent into solution at the desired temperature. The quaternisationproduct frequently already precipitates from the hot reaction mixture.

For the preparation of the compound of the formula (603), thestoichiometric amount of triethanolamine was first added to thesuspension of the sparingly soluble starting material of the formula(405) in dimethylformamide, so that the starting material goes intosolution in the form of the triethanolamine salt. The dimethyl sulphatewas then added at room temperature and the solution was stirred for 1/2hour at 60° C. and for 1/2 hour at 100° C., whereupon the quaternisationproduct precipitated out.

The compound of the formula (613) was obtained by refluxing (201) inethylene chlorohydrin for 12 hours and recrystallising the reactionproduct from water. In an analogous manner, (641) was prepared usingchloroacetonitrile at the reflux temperature, (650) was prepared usingbenzyl bromide at 130° C. and (651) was prepared using ethylbromoacetate at 100° C., the reaction time in each case being 2 hours.

In order to prepare the compounds of the formulae (670), (649) and(652), (201) and (204) were refluxed overnight in chlorobenzene with a10-fold excess of chloracetamide and, respectively, with ethylp-toluenesulphonate (25% excess).

The compounds of the formulae (656), (661) and (666) were obtained byboiling the compounds of the formulae (208), (301) and (237)respectively with chloroacetonitrile overnight. The compounds (662),(663) and (664) were prepared correspondingly from the compounds (208),(211) and (222) respectively in ethyl bromoacetate at 100° C. in thecourse of 2 hours, whilst in order to prepare compound (665), thereaction was carried out for 15 minutes at 140° C. Compound (660) wasprepared in chlorobenzene at 120° C.

If a quaternisation product could not be separated out from the reactionmixture, or could be separated out only as an oil, for example compound(615) or (638), the reaction mixture was completely evaporated in vacuoand the residue was crystallised from a suitable solvent, such as water,ethanol, n-propanol or mixtures thereof.

The compounds of the formula ##STR59## in which R₁ to R₅, A and n are asdefined in Table VI, can be prepared in a similar manner, usingcorresponding starting materials and, where appropriate, quaternisingagents.

                                      TABLE VI                                    __________________________________________________________________________    Compound                                                                      No.   n R.sub.1     R.sub.2 R.sub.3   R.sub.4                                                                             R.sub.5                                                                           A                             __________________________________________________________________________    701   0 SO.sub.2 OC.sub.6 H.sub.4 -p-Cl                                                           CH.sub.3                                                                              --        Cl    H   --                            702   1 SO.sub.2 OC.sub.6 H.sub.4 -p-Cl                                                           CH.sub.3                                                                              CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             703   0 SO.sub.2 OC.sub.6 H.sub.4 -o-OCH.sub.3                                                    CH.sub.3                                                                              --        Cl    H   --                            704   1 SO.sub.2 OC.sub.6 H.sub.4 -o-OCH.sub.3                                                    CH.sub.3                                                                              CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             705   0 SO.sub.2 C.sub.6 H.sub.5                                                                  C.sub.2 H.sub.5                                                                       --        Cl    H   --                            706   1 SO.sub.2 C.sub.6 H.sub.5                                                                  C.sub.2 H.sub.5                                                                       CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             707   0 SO.sub.2 CH.sub.2 C.sub.6 H.sub.5                                                         CH.sub.3                                                                              --        Cl    H   --                            708   1 SO.sub.2 CH.sub.2 C.sub.6 H.sub.5                                                         CH.sub.3                                                                              CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             709   0 SO.sub.2 OC.sub.6 H.sub.5                                                                 CH.sub. 3                                                                             --        CH.sub.3                                                                            3-Cl                                                                              --                            710   1 SO.sub.2 OC.sub.6 H.sub.5                                                                 CH.sub.3                                                                              CH.sub.3  CH.sub.3                                                                            3-Cl                                                                              CH.sub.3 SO.sub.4             711   0 CN          C.sub.2 H.sub.5                                                                       --        Cl    H   --                            712   1 CN          C.sub.2 H.sub.5                                                                       CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             713   0 COOC.sub.6 H.sub.5                                                                        CH.sub.3                                                                              --        Cl    H   --                            714   1 COOC.sub.6 H.sub.5                                                                        CH.sub.3                                                                              CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             715   0                                                                                ##STR60##  CH.sub.3                                                                              --        Cl    H   --                            716   1                                                                                ##STR61##  CH.sub.3                                                                              CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             717   0 COOCH.sub.2 CH.sub.2 OCH.sub.3                                                            CH.sub.3                                                                              --        Cl    H   --                            718   1 COOCH.sub.2 CH.sub.2 OCH.sub.3                                                            CH.sub.3                                                                              CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             719   0 COOCH.sub.2 CH.sub.2 OC.sub.6 H.sub.5                                                     CH.sub.3                                                                              --        Cl    H   --                            720   1 COOCH.sub.2 CH.sub.2 OC.sub.6 H.sub.5                                                     CH.sub.3                                                                              CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             721   0 COOCH.sub.2 C.sub.6 H.sub.5                                                               CH.sub.3                                                                              --        Cl    H   --                            722   1 COOCH.sub.2 C.sub.6 H.sub.5                                                               CH.sub.3                                                                              CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             723   0 COOCH.sub.2 CHCH.sub.2                                                                    CH.sub.3                                                                              --        Cl    H   --                            724   1 COOCH.sub.2 CHCH.sub.2                                                                    CH.sub.3                                                                              CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             725   0 SO.sub.2 NHCH.sub.2 CH.sub.2 OC.sub.6 H.sub.5                                             CH.sub.3                                                                              --        Cl    H   --                            726   1 SO.sub.2 NHCH.sub.2 CH.sub.2 OC.sub.6 H.sub.5                                             CH.sub.3                                                                              CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             727   0 CONH.sub.2  CH.sub.3                                                                              --        Cl    H   --                            728   1 CONH.sub.2  CH.sub.3                                                                              CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             729   0 CONH.sub.2  C.sub.2 H.sub.5                                                                       --        Cl    H   --                            730   1 CONH.sub.2  C.sub.2 H.sub.5                                                                       CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             731   0 CONHCH.sub.2 CH.sub.2 OCH.sub.3                                                           CH.sub.3                                                                              --        Cl    H   --                            732   1 CONHCH.sub.2 CH.sub.2 OCH.sub.3                                                           CH.sub.3                                                                              CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             733   0 CONH(CH.sub.2).sub.3 N(CH.sub.3 ).sub.2                                                   CH.sub.3                                                                              --        Cl    H   --                            734   1 CONH(CH.sub.2).sub.3 N.sup.⊕ (CH.sub.3).sub.3                                         CH.sub.3                                                                              CH.sub.3  Cl    H   2 CH.sub.3 SO.sub.4           735   0 CONHCH.sub.2 C.sub.6 H.sub.5                                                              CH.sub.2 C.sub.6 H.sub.5                                                              --        Cl    H   --                            736   1 CONHCH.sub.2 C.sub.6 H.sub.5                                                              CH.sub.2 C.sub.6 H.sub.5                                                              CH.sub.3  Cl    H   2 CH.sub.3 SO.sub.4           737   0                                                                                ##STR62##  CH.sub.3                                                                              --        Cl    H   --                            738   1                                                                                ##STR63##  CH.sub.3                                                                              CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             739   0                                                                                ##STR64##  CH.sub.3                                                                              --        Cl    H   --                            740   1                                                                                ##STR65##  CH.sub.3                                                                              CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             741   0 SO.sub.2 CH.sub.3                                                                         n-C.sub.4 H.sub.9                                                                     --        Cl    H   --                            742   1 SO.sub.2 CH.sub.3                                                                         n-C.sub.4 H.sub.9                                                                     CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             743   1 SO.sub. 2 CH.sub.3                                                                        CH.sub.2 C.sub.6 H.sub.5                                                              Cl        H     Br                                744   1 CN          CH.sub.3                                                                              CH.sub.2 C.sub.6 H.sub.5                                                                Cl    H   Br                            745   1 SO.sub.2 OCH.sub.2 CH.sub.2 OCH.sub.3                                                     n-C.sub.4 H.sub.9                                                                     CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             746   0 SO.sub.2 NHCH.sub.2 CH.sub.2 OCH.sub.3                                                    CH.sub.2 CH.sub.2 OCH.sub.3                                                           --        Cl    H   --                            747   1 SO.sub.2 CH.sub.3                                                                         CH.sub.3                                                                              CH.sub.2 COOC(CH.sub.3).sub.3                                                           Cl    H   Br                            748   1 SO.sub.2 CH.sub.3                                                                         CH.sub.3                                                                              CH.sub.2 CHCH.sub.2                                                                     Cl    H   I                             749   0 SO.sub.2 OC.sub.6 H.sub.4 -pC(CH.sub.3).sub.3                                             CH.sub.3                                                                              --        Cl    H   --                            750   1 SO.sub.2 OC.sub.6 H.sub.4 -pC(CH.sub.3).sub.3                                             CH.sub.3                                                                              CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             751   0 SO.sub.2 CH.sub.2 C.sub.6 H.sub.5                                                         CH.sub.3                                                                              --        Cl    H   --                            752   1 SO.sub.2 CH.sub.2 C.sub.6 H.sub.5                                                         CH.sub.3                                                                              CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             753   0 SO.sub.2 OC.sub.6 H.sub.5                                                                 CH.sub.3                                                                              --        CONHCH.sub.3                                                                        H   --                            754   1 SO.sub.2 OC.sub.6 H.sub.5                                                                 CH.sub.3                                                                              CH.sub.3  CONHCH.sub.3                                                                        H   CH.sub.3 SO.sub.4             755   0 CN          CH.sub.3                                                                              --        H         --                            756   1 CN          CH.sub.3                                                                              CH.sub.3  H     H   CH.sub.3 SO.sub.4             757   0 COOC.sub.2 H.sub.5                                                                        CH.sub.2 CN                                                                           --        H     H   --                            758   1 COOC.sub.2 H.sub.5                                                                        CH.sub.2 CN                                                                           CH.sub.3  H     H   CH.sub.3 SO.sub.4             759   0 SO.sub.2 CH.sub.3                                                                         CH.sub.3                                                                              --        H     H   --                            760   1 SO.sub.2 CH.sub.3                                                                         CH.sub.3                                                                              CH.sub.2 CN                                                                             H     H   Cl                            761   0 SO.sub.2 OC.sub.6 H.sub.5                                                                 CH.sub.3                                                                              --        Cl    2-CH.sub.3                                                                        --                            762   1 SO.sub.2 OC.sub.6 H.sub.5                                                                 CH.sub.3                                                                              CH.sub.3  Cl    2-CH.sub.3                                                                        CH.sub.3 SO.sub.4             763   0 COO(CH.sub.2).sub.3 N(CH.sub.3).sub.2                                                     CH.sub.3                                                                              --        Cl    H   --                            764   0 SO.sub.2 OC.sub.6 H.sub.3 -2,4-diCl                                                       CH.sub.3                                                                              --        Cl    H   --                            765   1 SO.sub.2 OC.sub.6 H.sub.3 -2,4-diCl                                                       CH.sub.3                                                                              CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             766   0 SO.sub.2 OC.sub.6 H.sub. 3 -2,4-diCH.sub.3                                                CH.sub.3                                                                              --        Cl    H   --                            767   1 SO.sub.2 OC.sub.6 H.sub.3 -2,4-diCH.sub.3                                                 CH.sub.3                                                                              CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             768   1 SO.sub.2 OC.sub.6 H.sub.5                                                                 CH.sub.3                                                                              CH.sub.2 CN                                                                             Cl    H   Cl                            769   1 CN          CH.sub.2 CN                                                                           CH.sub.3  Cl    H   CH.sub.3 SO.sub.4             __________________________________________________________________________

EXAMPLE 7

7.5 g of the compound of the formula (228) are stirred overnight at thereflux temperature in 35 ml of acrylonitrile and 5 ml ofN,N,N',N'-tetramethyl-1,3-diaminobutane. After cooling, the reactionmixture is filtered and the colourless residue is washed repeatedly withmethanol and dried in vacuo. This gives 8.2 g (96% of theory) of amixture of isomers (examination by NMR) of the formula ##STR66## whichcan be recrystallised from o-dichlorobenzene. Melting point 222° C.

3.9 g of this product are dissolved in 70 ml of anisole and 1.05 ml ofdimethyl sulphate are added dropwise to the solution at 120° C., withstirring. The mixture is stirred for a further 2 hours at thistemperature and allowed to cool and the product which has precipitatedout is filtered off, washed with anisole and isopropanol and dried. Inorder to separate it from uncovered starting material, the product isextracted with boiling water and the water-soluble fraction iscompletely evaporated in vacuo and boiled thoroughly with acetone. Thisgives 1.5 g of a mixture of isomers of the formula ##STR67## having amelting point of 220° C. (decomposition).

If the procedure described above is repeated, except that acrylonitrileis replaced by chloroacetonitrile andN,N,N',N'-tetramethyl-1,3-diaminobutane is replaced by potassiumcarbonate [1.05 mols per mol of the comound of the formula (228)], thisgives a mixture of the compounds of the formula ##STR68## (melting point202° C. after recrystallisation from anisole and n-butanol) and this isconverted, by quaternisation with dimethyl sulphate, to a mixture ofisomers of the formula ##STR69## (melting point 153° C., decomposition).

EXAMPLE 8

1.14 ml of dimethyl sulphate are added dropwise, at 100° C., to asolution of 4.73 g of the compound of the formula (243) in 50 ml ofdioxane and 30 ml of chlorobenzene. After the dropwise addition iscomplete, the mixture is stirred at this temperature for a further 1hour and the product is filtered off hot with suction and repeatedlywashed with toluene. This gives 5.7 g (95% of theory) of the compound ofthe formula ##STR70## which can be recrystallised from alcohol (meltingpoint 129° C.).

The compounds of the formula ##STR71## can be prepared in a similarmanner.

                  TABLE VII                                                       ______________________________________                                        Compound No.                                                                            R.sub.1             R.sub.2                                         ______________________________________                                        (807)     CONH(CH.sub.2).sub.3 N.sup.⊕ (CH.sub.3).sub.3                                                 CH.sub.3                                        (808)     COOCH.sub.2 CH.sub.2 N.sup.⊕ (CH.sub.3).sub.3                                                 CH.sub.3                                        (809)     SO.sub.2 NH(CH.sub.2).sub.2 N.sup.⊕ (CH.sub.3).sub.3                                          CH.sub.3                                        (810)     SO.sub.2 NH(CH.sub.2).sub.3 N.sup.⊕ (CH.sub.3).sub.3                                          CH.sub.2 C.sub.6 H.sub.5                        (811)     SO.sub.2 NH(CH.sub.2).sub.3 N.sup.⊕ (CH.sub.3).sub.3                                          CH.sub.2 CH.sub.2 CN                            (812)                                                                                    ##STR72##          CH.sub.3                                        (813)                                                                                    ##STR73##          CH.sub.3                                        (814)                                                                                    ##STR74##          CH.sub.3                                        ______________________________________                                    

EXAMPLE 9

0.2 g of sodium nitrate, 0.2 g of 80% pure sodium chlorite and 0.2 g ofoxalic acid or an equivalent amount of another organic or inorganic acidsuitable for this purpose are added to 100 ml of water. A solution ofthe fluorescent brightener of the formula (601) is prepared bydissolving 1 g of the said fluorescent brightener in 1,000 ml of water.1.5 ml of this stock solution are added to the solution described above.This liquor is warmed to 60° C. and polyacrylonitrile fabric weighing 3g is then added, the temperature is raised to 95° to 98° C. in thecourse of 10 to 15 minutes and the bath is kept at this temperature for60 minutes. The fabric is then rinsed in cold water and dried for 20minutes at 60° C. The fabric treated in this way displays a pronouncedwhite effect of good fastness to light. Similar effects are obtainedwith the compounds of the formulae (101), (201), (203), (204), (208),(210), (211), (215), (219), (222), (223), (229), (230), (231), (234),(235), (237), (238) to (241), (243), (244), (246), (248), (250), (301),(502), (605), (606), (609) to (614), (617), (620), (624), (625), (630),(632) to (635), (637) to (643), (646), (648), (649), (650), (652) to(658), (801), (802) and (805).

EXAMPLE 10

0.1 g of oxalic acid, 0.1 g of sodium acetate, 0.0125 g of sodiumbisulphite and 0.025 g of a polyphosphate as a complex-forming agent areadded to 100 ml of water. A solution of the fluorescent brightener ofthe formula (601) is prepared by dissolving 1 g in 1,000 ml of water. 6ml of this stock solution are added to the solution described above. Theaqueous liquor containing the fluorescent brightener is warmed to 60° C.and a hank of modified polyacrylonitrile ("Courtelle") weighing 3 g isput into the liquor. The temperature is raised to 98° C. in the courseof 10 to 15 minutes and the material is treated at this temperature for30 minutes. The material is then rinsed with cold water and dried. Thefibrous material treated in this way displays a pronounced white effectof good fastness to light. A similar effect is obtained with thecompounds of the formulae (605), (606), (609) to (613), (617), (620),(624), (625), (626), (630) to (636), (638) to (643), (646), (648), (649)to (658) and (802).

EXAMPLE 11

An aqueous solution is prepared which contains 0.3% of the fluorescentbrightener of the formula (601), based on the weight of the material tobe brightened. This solution is warmed to 30° C. Modified polyesterfabric (®Dacron 64) produced by co-condensation with 2 to 5 mol % of the5-(sodium sulphonate) of isophthalic acid, is then put into thesolution, a liquor ratio of 1:25 being maintained. The temperature israised to 120° C. in the course of 30 minutes and the bath is kept atthis temperature for 30 minutes. It is then cooled to 80° C. in thecourse of 15 minutes. The fabric is then rinsed in running cold waterand subsequently dried at 180° C. using an iron. It displays apronounced white effect. A similar effect is obtained with the compoundsof the formulae (604), (606), (610) to (614), (616), (617), (620),(624), (626 ), (630), (631) to (636), (639), (640), (642), (643), (646),(650) to (654), (657) and (658).

EXAMPLE 12

Freshly spun stretched polyacrylonitrile wet tow (corresponding to a dryweight of 3.0 g) is immersed, whilst still wet, for 10 seconds, at 20°C., in 100 ml of an aqueous liquor which contains 0.0005% of thefluorescent brightener of the formula (601), (605) or (624) and has beenadjusted to a pH of 4 with concentrated oxalic acid solution. The wettow is then rinsed briefly with water and dried at 90° to 100° C. A goodwhite effect on the polyacrylonitrile fibre is obtained in this way.

Brightening can also be effected, for example, at pH 6 (adjusted byadding sodium acetate). Raising the temperature of the dye liquor, forexample to 40° C., increases the rate of exhaustion.

Higher white effects are achieved by increasing the concentration offluorescent brightener, for example to 0.005%.

EXAMPLE 13

Usng a liquor ratio of 1:30 to 1:40, a fabric of cellulose acetate isput, at 50° C., into an aqueous bath which contains 0.15% of thecompound of the formula (605), based on the fibrous material. Thetemperature of the treatment bath is brought to 90° to 95° C. and thistemperature is maintained for 30 to 45 minutes. After rinsing anddrying, a good white effect is obtained. Similar effects are obtainedwith the compounds of the formulae (610), (611), (630), (632), (633),(646) and (649) to (653).

EXAMPLE 14

Using a liquor ratio of 1:30, a polyamide-6 fabric is put wet, at 30°C., into an aqueous bath which is at a pH of 9.5 and contains 0.2% ofthe compound of the formula (601), based on the fibrous material. Thetemperature is brought to 60° C. in the course of 10 minutes and thistemperature is maintained for 20 minutes. After rinsing and drying, thetreated fabric is ironed at 180° C. It displays a good white effect.Similar effects are obtained with the compounds of the formulae (605),(609) to (614), (617), (624), (626), (630), (631), (633) to (636),(639), (640), (642), (643), (646), (648), (652), (653), (654), (657) or(658).

EXAMPLE 15

An aqueous suspension of 100 parts of cellulose in 4,000 parts of softwater is mixed in a beater with an aqueous solution of 0.1 part of thefluorescent brightener of the formula (601) for 15 minutes, two parts ofresin milk and 3 parts of aluminium sulphate are added, the pump isdiluted with 20,000 parts of backwater, which contains 1 g of aluminiumsulphate per liter, and the resulting pulp is processed in aconventional manner to paper sheets. The resulting paper sheets arestrongly whitened.

EXAMPLE 16

2 g of the fluorescent brightener of the formula (601) are dissolved inabout 50 ml of hot distilled water. In addition, 80 g of a degradedstarch are dissolved in 1,000 ml of water at 90° C. to give a colloidalsolution. The brightener solution is then worked into the starchsolution. The resulting solution can have a pH value of 5.5 to 7. Usingthis size liquor, the surface of a sized printing paper is coated in asize press and the coated paper is dried at about 90° to 120° C. in thedryer part of the paper machine. This gives a paper of considerablyimproved whiteness.

EXAMPLE 17

An intimate mixture of 65 parts of polyvinyl chloride (suspension type),32 parts of dioctyl phthalate, 3 parts of an epoxidised soya bean oil,1.5 parts of a stabiliser (for example ®Irgastab BC 26), 0.5 part of aco-stabiliser (for example ®Irgastab CH 300), 5 parts of TiO₂ (rutiletype) and 91 parts of the compound of the formula (605) is milled on acalender at 150° C. to give a film. The resulting film displays apronounced white effect. Similar effects are obtained with the compoundsof the formulae (611), (624), (626) and (630).

EXAMPLE 18

An aqueous solution is prepared which contains 0.3 g of the fluorescentbrightener of the formula (611), 0.3 g of an adduct of 35 mols ofethylene oxide and 1 mol of stearyl alcohol, 0.3 g of an adduct of 8mols of ethylene oxide and 1 mol of p-tert.-octylphenol, 270 ml ofdeionised water and 30 ml of ethanol (95%). Cellulose acetate fabricweighing 8 g is padded in this solution (liquor pick-up 60%). Thetreated fabric is then dried in a drying cabinet at 70° C. The fabricdisplays a good white effect. Similar effects are obtained with thecompounds of the formulae (612), (617), (624), (637), (639), (642),(643) and (654).

What is claimed is:
 1. A process for optically brightening organicmaterial selected from polyacrylonitrile, modified polyacrylonitrile,modified polyester, cellulose acetate and polyamide, which comprises theincorporation in, or application to, the material to be brightened of a2-phenyl-5-benzimidazol-2'-yl-furane of the formula ##STR75## in whichR₁ is a sulphonic acid group or an ester or amide thereof, a carboxylicacid group or an ester or amide thereof, a cyano group, atrifluoromethyl group or an alkyl- or aryl-sulphonyl group, R₂ is alkylhaving 1 to 8 carbon atoms, alkenyl having 3 to 4 carbon atoms,cyclohexyl, hydroxyalkyl having 2 to 4 carbon atoms, alkoxyalkyl havinga total of 3 to 6 carbon atoms, carboxyalkyl having 2 to 6 carbon atoms,carbalkoxyalkyl having a total of 3 to 6 carbon atoms, cyanoalkyl having2 to 4 carbon atoms, carbamoylalkyl which has 1 to 6 carbon atoms in thealkyl moiety and is unsubstituted or substituted on the nitrogen atom by1 or 2 alkyl having 1 to 3 carbon atoms, benzyl which is unsubstitutedor substituted by chlorine, methyl or methoxy, dialkylaminoalkyl havinga total of 3 to 7 carbon atoms or phenethyl and, if n is the number 0,also hydrogen, R₃ is hydrogen, alkyl having 1 to 6 carbon atoms,hydroxyalkyl having 2 or 3 carbon atoms, cyanoalkyl having 2 to 4 carbonatoms, carboxylate having 2 or 3 carbon atoms, carbamoylmethyl which isunsubstituted or substituted on the nitrogen atom by 1 or 2 alkyl having1 to 3 carbon atoms, alkoxycarbonylalkyl having a total of 3 to 6 carbonatoms, alkenyl having 3 or 4 carbon atoms or benzyl which isunsubstituted or substituted by chlorine or methyl, R₄ is hydrogen,chlorine, bromine, fluorine, carboxyl, carbalkoxy having a total of 2 to5 carbon atoms, alkoxyalkoxycarbonyl having a total of 4 to 6 carbonatoms, benzyloxycarbonyl, cyano, sulpho, alkylsulphonyl having 1 to 4carbon atoms, carbamoyl or sulphamoyl which are unsubstituted orsubstituted by 1 or 2 alkyl groups having 1 to 4 carbon atoms, orsulphonic acid phenyl ester or trifluoromethyl, R₅ is hydrogen, chlorineor methyl, R₆ is hydrogen or chlorine, n is the number 0 or 1 andA.sup.⊖ is a colorless anion equivalent to the cation of the fluorescentbrightener.
 2. A process for optically brightening organic materialselected from polyacrylonitrile, modified polyacrylonitrile, modifiedpolyester, cellulose acetate and polyamide, which comprises theincorporation in, or application to, the material to be brightened of a2-phenyl-5-benzimidazol-2'-yl-furane of the formula ##STR76## in whichR₁ is a sulphonic acid group, a sulphonic acid phenyl ester which isunsubstituted or non-chromophoric substituted, alkylsulphonyl having 1to 4 carbon atoms, benzylsulphonyl, phenylsulphonyl which isunsubstituted or substituted by methyl or chlorine, cyano,trifluoromethyl, --SO₂ NY₁ Y₂ or --CONY₁ Y₂, in which Y₁ is hydrogen,alkyl having 1 to 8 carbon atoms, alkenyl having 3 or 4 carbon atoms,cyclohexyl, hydroxyalkyl, having 2 to 4 carbon atoms, alkoxyalkyl havinga total of 3 to 6 carbon atoms, carboxyalkyl having 2 to 6 carbon atoms,carbalkoxyalkyl having a total of 3 to 6 carbon atoms, cyanoalkyl having2 to 3 carbon atoms, benzyl, which is unsubstituted or substituted bymethyl or methoxy, phenyl which is unsubstituted or substituted bychlorine, methyl or methoxy, dialkylaminoalkyl having a total of 3 to 7carbon atoms or phenethyl, Y₂ is hydrogen, alkyl having 1 to 3 carbonatoms, alkenyl having 3 or 4 carbon atoms or hydroxyalkyl having 2 to 4carbon atoms and Y₁ and Y₂ together with the nitrogen atom are a 5- or6-membered aliphatic heterocyclic ring, which optionally can contain afurther heteroatom and which which is unsubstituted or substituted bynon-chromophoric substituents, R₂ is alkyl having 1 to 8 carbon atoms,alkenyl having 3 to 4 carbon atoms, cyclohexyl, hydroxyalkyl having 2 to4 carbon atoms, alkoxyalkyl having a total of 3 to 6 carbon atoms,carbalkoxy having 2 to 6 carbon atoms, carbalkoxyalkyl having a total of3 to 6 carbon atoms, cyanoalkyl having 2 to 3 carbon atoms, benzyl whichunsubstituted or substituted by chlorine, methyl or methoxy,dialkylaminoalkyl having a total of 3 to 7 carbon atoms or phenethyland, if n is the number 0, also hydrogen, R₃ is hydrogen, alkyl having 1to 6 carbon atoms, hydroxyalkyl having 2 or 3 carbon atoms, cyanoalkylhaving 2 or 3 carbon atoms, carboxyalkyl having 2 or 3 carbon atoms,carbamoylalkyl having 2 to 4 carbon atoms, alkoxycarbonylalkyl having atotal of 3 to 6 carbon atoms, alkenyl having 3 or 4 carbon atoms orbenzyl which is unsubstituted or substituted by chlorine or methyl, R₄is chlorine, bromine, fluorine, carboxyl, carbalkoxy having a total of 2to 5 carbon atoms, alkoxyalkoxycarbonyl having a total of 4 to 6 carbonatoms, benzyloxycarbonyl, cyano, sulpho, alkylsulphonyl having 1 to 4carbon atoms, phenylsulphonyl which is unsubstituted or substituted bychlorine or methyl, benzylsulphonyl, sulphonic acid phenyl ester whichis unsubstituted or non-chromophoric substituted, or --SO₂ NY₁ Y₂ or--CONY₁ Y₂ wherein Y₁ and Y₂ have the meanings given above, R₅ ishydrogen, chlorine, alkylsulphonyl having 1 to 4 carbon atoms, sulpho,methyl, sulphonic acid phenyl ester which is unsubstituted ornon-chromophoric substituted or --SO₂ NY₁ Y₂ wherein Y₁ and Y₂ have themeaning given above, R₆ is hydrogen or chlorine, n is the number 0 or 1and A.sup.⊖ is a colourless anion.
 3. A process according to claims or2, which comprises the use of polyacrylonitrile or a copolymer thereofas the organic material.
 4. A process according to claims 1 or 2, whichcomprises the use of a polyester modified with acid groups as theorganic material.
 5. A process according to claims 1 or 2, whichcomprises the use of 0.001 to 2% of the fluorescent brightener, based onthe weight of the material to be brightened.